Silicone is your sworn enemy! Even small trace amounts can make it impossible to repair the finish on a guitar. And most furniture polishes (yes, that includes Pledge) contain silicone. Because nothing can bind to it, any touch-up paint or clear-coat will come out with 'fish-eyes'.

Those of you who use Fast Fret to make your finger boards nice n' slick had better hope you never need to refinish the neck.

And if you take your axe to a luthier for a repair, you risk contaminating their workshop. That stuff is almost impossible to get rid of! It can't be washed off. Any cloth or plastic exposed to silicone will have to be thrown away.