Adhesive removers work very well!
Once product I've used for over 30 years is DuPont Prep-Sol 3919S
. This is a chemical specifically developed for the painting industry for thoroughly cleaning and removing grease, oils, silicones, waxes, sealants and just about anything else prior to automotive refinishing.
While DuPont Prep-Sol 3919S
works and works well, I've found another product designed to perform in the same manor, Klean Strip Prep-All.
I've been using this for the past 2 years with 100% success and it's half the cost of the DuPont product above... Klean Strip Prep-All -
Available in gallons, quarts, and spray cans....