one way i learned from the numerous videos is...
jeng jeng jeng
just put cut up PVC pipes on the wheels and use them as tires. hahahahaha
im only half serious. i may have mistaken those things for PVC pipes when they're something else. only enthusiasts will know better. what i saw in the video was, this guy slipped on this smooth plastic tube; which is cut to the tire's width onto the rubber tire. the diameter should be a fit (almost same) to the whole tire assembly. i think im wrong, but they did look like PVC pipes (quite big size), and they dont have much traction.
again, DISCLAIMER : my statements are solely based on my observation of downloaded videos, and i do not claim expertise or knowledge in this article. :D sorry if im wrong. :p