This is aimed at racers who use VP-Pro Tires but applies to every brand of tires. I get complaints sometimes that our Tires don't stick and always fall off, so the rubber must be bad. I have only had my tires fall off a few times in the last 15 years, but I do the same procedure every time when I glue my tires because when I started racing 1/8 driving for Proline, my tires came unglued in the mains all the time back in 2001.
Now I know what you are thinking, LOL no one dremels their wheels any more, that is old school and a waste of time. So let me explain why this is needed on VP-Pro tires (an every other brand if the same circumstances apply). The tires come from the factory with mold release on the rubber. The first step is to clean the beads with the right stuff. Many pros say simple green works best but it depends on the compound. With VP-Pro tires, non-chlorinated brake clean works better from my tests (I tried everything). But here is the Reason you Must dremel the wheels too - The tires are shipped in a sealed bag from the factory with the wheels in the same bag. While the tires are in the bag with the plastic rims, the mold release touches the wheels and soaks into the plastic. Now the rims are contaminated just like the tires. When you clean the tire bead (and even the rim bead) but do not dremel the rims, the mold release is still in the plastic wheel and the glue won't stick. So your tires fall off.
Now if you never let your tires touch the wheels before cleaning them, you can get away with not dremeling the rims. But if you always dremel the rims, the glue always sticks better and you won't have this issue if the rims did contact the tires before being cleaned.