Gawd, only the Japanese could come up with something like this! Take 6 women and fill their arses with a milk enema. Then make them race up and down what looks like a sports hall with both hands and feet on the floor. The first one to let the milk escape or the last to finish the race is knocked out.
Is it sexy? LOL - nope, not to me anyway. Is it funny? Hell yes!
I wouldn't call this scat. But in answer to your question I have a theory that the Japanese are into a lot of extreme stuff because their society is very rigidly structured and they have to have an outlet for their wilder sides.