With all due respect to the males that have offered to do it in white T shirts ...
As Ian said , moobs are abundant ... 6 packs seem to be a little short on the offerings.
Maybe if you were being 'objectified' as us women who are reg refered to as 'tank polishers' are being then you would have a different opinion to this, the joking about the ample chests some of us have is one thing, taking part in something that is designed for males to leer at is another.
As I said , to raise funds yes I would do a bike wash, would do a wet T shirt one (lets face it would prob get wet & end up as a water fight at some point)
, but not a white wet T shirt with nothing under it