rubber bumper cracked paint repair

I did some Auto Body repair way back in the early 80's, when very few bumpers were rubber, at least I never worked on any. My 90 Mustang has had some bumping and grinding done to the rubber bumpers. The paint job has cracked quite aways around the impact area. If it was metal I would just use some paint striper and feather sand the edges and be done, but every paint stripper I have seen very clearly states "for removal of paint off of the metal". Is there any product out there that will remove paint from a rubber bumper?

Any help would be greatly appreciated.