My best tip is regular cooking oil! The oil will dissolve any sticky residue, then simply wash the oil off with dish soap! This is something that I have done a billion times and has worked each and every time!
-Simply put the oil on paper towel
-then blob the sticky residue
-"scratch" off with your finger nail or something soft
-if all the residue is not ALL off start over
- residue all off wash area with rag soaked in hot water and dish soap
-rinse area well with plane water
Presto just like that, it is good as new!
TreeFrog