I have used Orange Solvent for years, before it became 'commercially' available  and had great success with it removing glue- especially after mylar removals.
I am sure it is the same as JWJ's spray version - or at least similar concept.
I never 'left it on' long , and it always gave good results - easily.

I have been told that it WILL remove paintwork but man, in my experiences , you would have to rub hard and long for that to happen.