@bargainsgirl Perhaps either of those things might work, but I'd call Stamina and ask.
Because as I recall, before I replaced my old reformer, and my wheels were getting the same way, I think I put some kind of lubricant on it...I forget exactly what...but I think they just got gummy, sticky.
If it was me, I'd call Stamina. They have a good customer service dept. Their website might even answer things like this