WD-40 works well. Just make sure it's cleaned off well if planning on waxing any time soon. Works great on removing tar and bug guts off of the tow vehicle too without hurting the finish.
I will have to make a note about Right Guard. That's a new one. If it works, at least the Summers might be a bit more comfortable minus the humidity inside!
Mayonnaise might make me think of BLTs. Never a good thing for me when food gets involved. Same with peanut butter.
Be careful with anything used at bodyshops for stripping decals or glue residue. A lot of these solvents need special attention. Due to the fact that they are sold taking into consideration that the buyer knows how to use it. They can be quite a bit more aggresive and remove more than you may want (paint).