I have quit breeding crix and switched to roaches, too. However, when I was breeding crix, I routinely had 5000 on hand and only cleaned the bin every 6-8 weeks. I have found that:
1. If you're feeding them potato...STOP. Not only does a day old potato reek, it makes the crix waste smell worse.
2. If I fed mine dry cat/dog food, apple and collard or mustard greens exclusively, I had no more odor than with my roaches. Honest. The dog/cat food was an expensive holistic brand I feed my dogs, so I don't know whether something in my particular brand of dog food was helping, though.
3. Dead crix stink to high heaven. If they start dying off, they'll stink no matter what until you completely clean the bin.
4. Control the humidity in the bin. When crix respire, they release carbon dioxide and water just like we do. If you don't keep the humidity down, their waste smells way worse.
Please note that if you stick your face immediately above the bin, even roaches have some aroma despite what you may read on the Internet.
BTW: I switched to roaches not because of smell, but because I didn't have to deal with separating the nymphs from the adults. It simplifies breeding SOOOOOOOO much. Our crix never really bothered us, smell-wise.
Frank