I’ve had a black vinyl butt plug for two years and I think that a chemical film or something has developed on the surface that makes it burn when I insert it into my girlfriend’s ass. Would an automotive-type vinyl restorer make my butt toys last longer?
Latex rubber, jelly rubber, and vinyl sex toys are inexpensive for a reason: they do not last forever. I recommend that folks replace toys made of these materials after twelve months for the exact reason you report: the material starts to break down, and often causes stinging, burning, itching, and other discomfort when used.
No, a vinyl restorer sold in automotive supply stories is not a good idea; not only will it not help stop the toy from deteriorating, but you do not want any product like that (or traces of it) in your ass! Throw the toy and buy a new one, or, for your next purchase, try a higher quality silicone toy. Silicone can be much more pricey, but it’s also a lot more resilient. My silicone toys have lasted for many years, and some brands even come with lifetime guarantees.