This is a little trick I found somewhere down the road for cleaning grime off of my fretboard when changing strings. I use strings that take a LONG time to get old, so I change them every couple of months or so, and grime tends to accumulate. Enjoy, and please subscribe to my channel to help me share these lessons with the world. U can also go to licknriff.com for more guitar articles and lessons. Twitter: @licknriff