Hey Guys, trying to replace my pickguard on my Fender 1995 USA P-Bass. The Tone knob set screw is buggered up to the point that I can not get that lil thing to turn. It is a tiny flat head set screw on a solid shaft in a chrome knob. Looks like it may be a brass screw? It was full of grime from nearly 20 years of playing live and practice's. I can see the head and it is not stripped, just really stuck. Have been soaking WD40 (applied w/ a tiny brush) in the hole and used a small flathead screw driver. And nothing. It worked on the Volume, but not the tone.... Any tips? Should I seek out a better cleaner/lube or better tool?