Patience is key with the oven method, not worth burning fingers.
I have done the vapor method as well with acetone and it left a stringy mess with gummed up glue all over the place, never doing that again :( However the inserts were not damaged, ha!
Only time I use acetone is when I want to...
I have found that acetone will damage the wheel insert by causing it to shrink and crack after it dries :(
To re-use both the tire and insert I've had the best luck with the oven method.
Pre-heat oven to 350°F then turn off oven, Insert wheel on cookie sheet and wait for oven to cool... pull...