I used to wash my headgear after every session, simply because I knew it collected the sweat and dirt it touched. Why gi players don't wash their belt is beyond me. Ankle sleeves should be washed after jiu jitsu, just as socks need to be washed after football.
Dude, if you trained at our gym and I found out you were wearing gear to multiple practices without washing, I'd be forced to choke the piss out of you.
In love, of course.
Wash your stuff after every training session. Seriously.