Poster paints also work, and they are inexpensive. They will crack and rub off on everything. I advise using the outside showers to wash them off, too!
You can also sponsor an impromptu body painting session with others, if you like.
I painted my wife up as Cassandra, Mistress of the Dark one Halloween.
I used black poster paint and painted a dress, with plunging neckline and back, with a slit up one leg.
When we got to the main dining room, a man asked, "Young lady, do you have anything on under that dress?" She missed her line, "Dress? What dress? I don't have a dress on!"