When I went riding earlier in the week, I put a slab of chocolate into the back pocket of my jersey - something to keep me going when the energy levels started to sag 30km from home. It didn't melt, as it was good quality 70% Lindt chocolate, but I did manage to smash it up by crushing it between the seat and my back when I waited at traffic lights (it's a long jersey, so the pockets sit further down my bum than my regular jerseys). I ate most of it, but a few chunks remained in the pocket when the jersey went into the machine later that night.
When I went to pull the jersey on yesterday, I found a few chunks were still in the pocket. They were still edible, as I discovered (why waste good quality chocolate?), and in good shape (since I wash in cold water). But I wouldn't recommend it. I know we are always told to wash our fruit and vegetables before eating them, but putting chocolate in the wash is probably taking it a bit far.