Do not burn incense or smoke in the same room as your reptiles. Smoke = respiratory infections when done in excess. Incense in particular is designed to produce lots of smelly smoke - which we humans love, but snake respiratory systems don't enjoy so much. In moderation I doubt it's going to kill anything, but if your wife is complaining any time a snake drops a deuce, she is likely to also use whatever smelly products she can to eliminate the smell, especially when you're not home to immediately clean it.
I keep 12 snakes in my bedroom without any real noticeable odor. I keep almost all of them on papertowel, and clean when there's feces or a significant amount of urates.
Maybe try changing to a different style bedding, or clean the actual cages using something else. I personally love Clorox Wipes - they smell nice and pick up all the poo and other gunk that gets in my snake cages. When it's sunny out and I have time, I'll drag out a few cages and hose them off and let them dry in the sun.
Depending on how old your cages are, the cages themselves might just be funky. When I kept chickens, we de-stunk the chicken stuff by hosing it off with water, bleaching it, hosing it off again, and then letting it dry for an hour or so in the sun. Generally, whatever the bleach doesn't kill the sun will, so not only did our chicken coop not stink, but we had nice healthy chickens. Chickens are an animal that can smell a lot worse than snakes, so if that doesn't help, I don't know what will.
Try maybe sticking some bounce sheets inbetween cages as well. I do that in the closet I keep my rodents in, and it makes it smell less rodent-y... and rodents are another animal that tends to smell much, much worse than the snakes do.
Good luck!
~jenny
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"We call them dumb animals, and so they are, for they cannot tell us how they feel, but they do not suffer less because they have no words."
- Anna Sewell (1820-1878)