[Kevin Sevcik]

Ask the Q&A, obviously. But if you want my opinion, the answer is going to be no. There's a specific list of materials the bumpers can be made out of, and "slippery spray" isn't one of them. The bumpers ARE supposed to be covered with rugged, smooth cloth, however. If you can find red and blue cloth that's slippery enough to meet your needs but still counts as rugged, then you can make new bumpers or recover your old bumpers at the event.

I'll note you're in luck with that, because most teams have to opposite problem. Over the bumper pickups seem to work better with a grippy bumper, but that's not allowed at all in the bumper rules.