The quick question: Is the S&W bore and action cleaner safe for my 15-22? I'm worried about polymer melting away.

The long story. Used some similar stuff of a different brand. Melted the finish on some plastic grips. I know its not the same material, but just being cautious...

I haven't used this product, but according to the Midway catalog it is safe for synthetic stocks. Read the label carefully to be sure it doesn't have any warnings that might affect your 15-22.