If it starts I just hold a cap full of Cellulose thinners near the belt whilst it's running and it cures it instantly for a long time.
I learnt the trick from a very old experienced Engineering colleague of mine except we would use CTC which is no longer readily available.
Would that be good for a maintenance job as well as a curative job?
I see no reason not too, I have only had to do it once in 5 years to my present car though.
We used to get the CTC out of those old brass fire extinguishers

, it was heady old stuff though.