Aspen is almost odorless. Cypress has a bit of an earthy smell. 

Unfortunately, rodents stink a little when you have a lot, especially males. I have never tried vanilla (where did you hear that? Interesting idea) but I would worry that if you mess with the odor they won't be appealing to your snakes.

Maybe an air filter in the rodent space?

I only have 3 boa's so it may be an issue of quanity but I never had an issue with smell. I suppose rats can be smelly critters in general generating waste more often then I would assume the snakes but since they are in the attache garage I'm assuming your saying the in house smell would be coming from the snakes? I never used the Tek-fresh but seen it was made from virgin wood pulp, the same stuff as paper towels & tissue paper meaning it's probably pretty absorbent & easy to hide things in if mulchy. I would make sure I had secure water bowls that down spill often & try cleaning completely more often instead of just spot cleaning.

I have 16 snakes and I use aspen, I never smell them. For rodents I used wood pellets and it made them not smell at ALL unless you were right there bending over their cages, because it soaks up all the smells and gradually breaks down. That would be worth trying for rodents if you can find it.

I use aspen and like the smell. Spot cleaning when they go is ideal. 
As for mice; they just stink. A lot of ventilation is the best way to get the smell out... I like ventilated racks but those are very, very expensive. Changing out cages completely is a stressor for mice though-- spot changing the corners they go to the bathroom more frequently might help. Content mice go in one or two corners only. The amount of mice per cage too will affect smell. 
Rats don't care much about changing out and they don't  

I really don't smell my rodents. I use aspen with a thin layer of alfalfa pellets (rabbit food at farm & garden stores) underneath. The alfalfa seems good & helps soak up the urine.

I second NikiP. I breed English or show mice in my home. Aspen with alfalfa works great. Then use a kitty litter scoop to get the corners about every third day. Vanilla in the water will work...but it has to be true vanilla extract NOT the immitation stuff. Bio oder for ferrets works too.  So it's not cheap. Just a couple of drops per bottle. Males will mark EVERYTHING overnight if you change the whole cage. Leave a papertowel tube or other hide object in the cage to keep them from going crazy marking again.Then think about getting a air filter and or open a window with a fan to get air moving.

Buy frozen....they smell better....

I use aspen for my BCIs... I don't smell them.. but, I don't like how aspen smells.  At all.

on a related note, I don't grow up my own feeders but I have a question for those who do. if you raise them on cedar or pine, wouldn't it be harmful to the snake? they're going to have the residues on their fur if they live on it, even with all the grooming?

Cedar shouldn't be used. It's just not safe.

Have heard kiln dried pine is ok as it removes the oils. f

Personally I don't use either, why risk it?

^that's kind of what I was thinking.

Cedar is BAD.  In all ways, as said.  You don't want to feed rodents raised on cedar to snakes.  There is actually plenty of research now that the cedar is just as bad for the rodents as the snakes.  Pine can be dried properly to remove oils, but apparently this isn't as simple as it sounds, and allot of the bedding hasn't been treated properly,  I read into this allot years ago, and I came to the descision that it just isn't worth it. 

I can't help you with the rodentst.  They smell, and always will to some extent IMHO.  You can certainly reduce it, but it will always be an uphill, mostly loosing battle. 

As for the snakes, the easiest way to reduce smell is paper, every time someone defecates/urates, remove and clean (I use F10, that stuff is wonderful).  I have 30+ snakes in a small snake room, and no lingering smell whatsoever.  To the extent that I can smell when someone goes. 

As fr the wooden substrates, cypress works great.  Very absorbent, and the natural slightly wooden smell seems to cover well.  Another thought I have noticed over the years, when people "spot clean" wooden substrates, often they don't remove enough.  When a snake defecates, there is usually more moisture released than you can see even an hour later, even on paper.  That dries into the substrate quickly.  So if you are at work all day, or whatever, come home and just remove the visible defecation, you are leaving substrate with dried waste.  Take a good chunk of the substrate out all around that area.  That will help a great deal as well. 

Also on the cypress front, allot of the cypress mulch sold now is "blended", with no info on what it is blended with.  I avoid that personally, as if there is pine in there (which with the amount of pine used in the world, I'd bet there is some in some of that stuff), I highly doubt it has been treated or dried properly to remove any oils. 

You can always use plain old newspaper for your royals; there's no smell other than what's in their poop. I use newspaper for nearly all of my herps, including my ball pythons, and it works wonderfully; in addition, their poop/pee/urates are incredibly easy to spot on paper. You seem to be doing the cleaning quite often, whuich is good. Just keep trying various methods. I know nothing about vanilla for rodents, though, although I'm thinking, based on what I know of rat biology, it wouldn't be healthy for them.

I'm working on an exhaust vent for my rodents.  To clear out all the air in the room in a short amount of time (few minutes). I plan to run it 3 times a week, maybe more depending on what is neccessary. I do use pine, and I don't have any issues. I can't imagine the large rodent breeders don't use aspen as a bedding, and I don't know of any cases that it's caused problems. I also use pine pellets as a base to help absorb some more urine and smell. 

As for the snakes, I've never had good luck with ball pythons on aspen. It tends to mold when wet and I need to wet my cages significantly for good sheds. I do like cypress, it's great for the humidity, lasts long, great for spot cleaning, but it does have an earthy smell when wet or moist. I'm currently using news paper, as I have a lot of it  (free) and it's simple and clean. My atb's do still have cypress though. It works great for them, depending on the ventilation in the cage (too little and it will mold as well). 

Thank you all for the comments and suggestions.  I've been poking my nose around and the worst smell, in my opinion, is fresh, out of the bag tekfresh substrate.  It just has a weird natural smell to it.  I recently loaded up a new rack with bedding, so it was just dominating the house.  This smell does disipate after a couple of weeks.

No doubt rodents stink, but I really stay on top of their cleanliness so that's not usually too bad.  I did do some more research on the vanilla trick.  I didn't find anything too scientific about it, but there are a handful of people that claim it works for them.  The ratio of water to vanilla though is pretty high.  At my volume, I'd be using a whole lot of vanilla!  It also seems a bit gimicky to me, so I'll stick with frequent cage cleaning.

The ultimate goal is to move my entire operation out of the house and into its own facility :)