Thank you. I didn't know that. Brake cleaner it is, then.
I'll do some experimenting with carburetor cleaner spray, however, for I've used it for years in many applications. My guess is that the vulnerability of the rubber would depend upon its specific composition, of which there are, like, hundreds.
70% (or stronger, I use 91%) rubbing alcohol would also do well. I've used it to clean oil from rubber parts.