I went for two as well, since the foot is a relatively small area to have 3+ hands poking and scribbling across it. Also, assuming there was enough room to tickle with that many hands, there's always the deadening of sensitivity that tends to happen when tickling the same areas over and over again. Some people claim this isn't true. I'm not gonna debate it though, because there's too many people in the world to say that one person couldn't be constantly ticklish on his/her feet. I've never met anyone who has, though, and still feel the most effective method is to cycle through different areas to tickle so the brain doesn't become familiar with the sensation.