One will remove the cap from another's body wash container, and ejaculate inside of it, where it shall lay unnoticed until the unsuspecting victim showers next.
If placed inside a shampoo bottle, (head and shoulders works best) it is known as Austrian Hair Gel
A particularly hairy man may experience yogurt flakes when engaging in an Austrian Cheese Bath.
"I came in your body wash, you bathed in my spunk!"
"Youre a fuckin douche!"
"I know! Lets go make ravioli..."