I would have to say "Can your pussy do the dog." I just so happened to pick up the original 45 of Dall Raney and the Umbrellas "Can your Hossie do the dog." this is where the Cramps got the idea for their song. I will bring it to HRW to let ya'll check it out!
Later,
Junior
I thought it was from Rufus Thomas' "Can your monkey do the dog". Later covered by Link Wray too.