A service advisor at a vehicle repair shop recommended belt conditioner to help ensure longevity of rubber belts (timing, serpentine, etc.) and as a possible inexpensive fix to various engine noises.
Belt conditioner comes in a spray bottle, and you simply spray it onto the exposed surface of any rubber belt.
Although he highly recommended the product (and it is much less expensive than any repairs), I am concerned that such a conditioner would be counter-productive. It seems like a belt conditioner could attract dust and debris, as well as form a gummy residue on pulleys.
Are belt conditioners safe to use?