I've noticed that sometimes when I wear my dancebelt all day, after taking three or four classes without changing in between, that the sweat adds up, and the dancebelt starts to have an odor -- but I call it that "masculine-man scent!"
If I don't shower every day, the second or third day there can be a more rauncy odor, something like "onions." My solution, to shower every day! I often clean my pubic area with a wash cloth in between, to keep that area clean. I had a couple of European friends who used to do this, kind of a sponge bath, at noon and after work.
Washing a dancebelt is another topic. I find that if I wash it too often, the material kind of breaks down, and sometimes you grab a dancebelt and toss it into your dancebag when it hasn't dried yet. My solution for this is to buy a few dancebelts, and wear them on alternating days, giving them time to air out in between classes. As I said, I get lazy about laundry. With a few dancebelts, it's easier to wash them together at one time.
One more thing....I used to play a lot of polo, and would also work my horses every morning, early, before I showered. Once again, being lazy, I wouldn't wash my jockstraps that often. I think the combination of not having showered first with the not so clean jockstrap was what was responsible for the the odor build-up there. I'd bet anyone who does other athletics experiences the same problem with their jockstraps.
I hope you find a solution that works for you! balletboy[/i]