SEND AN ANONYMOUS EMAIL. Make a fake email, or fake facebook account, or fake myspace, whatever, and EMAIL HIM or MESSAGE HIM and tell him that he smells and people wherever he goes know it, so he must wash with antibacterial and wash often, and wipe (tell him to even use wet-ones, maybe he needs that), and that he must use a full capload of laundry detergent with every wash and a sheet of fabric softener with every dry. If he is stinking up furniture or the air, you should get some high strength febreeze for the furniture/fabrics and odor neutralizer (not those flowery air fresheners) to make things smell better. Crack open windows. And run some things you don't care about in the washer with lots of detergent and in the dryer with tons of fabric softener sheets to help those get clean.
SO SORRY
-------
"If god hates anyone based on what they prefer...
then god himself is a loser.... and should GTFO...." - ijustdontknow
Could you tell your RA? Have them take the blow? 
Patron