That was just to be funny. The vat of sour cream and lederhosen are actually pretty irrelevant. lol.
I should have clarified a bit more. He has to sustain an actual hop. Simply being on one foot is not enough. If he stops hoping for too long, like 5 seconds, time returns to normal. I'd imagine that would make it incredibly hard to do anything, and you'd likely have very little time, especially since any number of things could cause you to lose your balance. Even if time is slowed or frozen, you can still trip over inanimate objects, or bump into someone.
And RW/FF, is really only good for a few seconds, so it really doesn't do much good. For instance, he can rewind time, but only can go back 10 seconds.
And then once he stops hopping it all goes back to how it was before?