I mean, I would say it depends on how ticklish the person in question is, and how skilled the makers are. For somebody feather ticklish, any spinning machine, like a fan, could be made into a tickling machine. For somebody who needs a firmer touch though, it's a little more difficult. I remember seeing tickling shoes somewhere that had little...spinning top like items built into the soles, but I can't say how good they worked, even though they looked pretty cool.