The answer is, it depends. I agree that for the most part, it is impossible.
I have used the tearmender method and that works well on Hurricane and Butterfly rubbers but does not work at all that well on ESN rubbers.
That method is basically applying 2-3 thick layers of tearmender to the rubber with glue already on it. Let it sit for 24-48 hours (the longer you let it sit and let the tearmender harden, the easier it is to pull the tearmender and the glue off in one single scoop). Then pull the tearmender along with the remaining glue off the rubber completely.
Interestingly, that method works well with hurricane. Probably because the sponge is thick and hard, so the glue and tearmender can come off in one single motion (or 2-3 motions at most).
For Butterfly rubbers, this method works ok. Meaning, as I pull the tearmender off along with glue, I might start pealing the combination off but after 20 seconds or so, that tearmender/glue layer breaks off and I have to start pealing from another corner of the rubber. I would say it takes 4-5 tries to get that off with Butterfly rubbers?
finally for ESN rubbers, it takes a lot of careful stripping to take that layer off and the rubber and sponge are still moderately damaged despite the best effort.
In conclusion, the answer is no. And you have to ask yourself how much time do you want to spend peeling the damn layer of glue off?
If you are a college student and the rubbers are expensive to you, then go ahead and do the tearmender method. If you are a professional (lawyers, doctors or engineers, etc.), then don't bother; it is not worth your time because you could make money with that time. If that's case, either reboost the rubber with more booster or throw the rubber away and get a new one.