It been done before but perhaps i'd suggest starting out with "prepared guitar"... for a long time i was doing it but then i got tired of it. There are/were a number of guitarists who specifically have used "prepared techniques" in the improv scene that are well known, Kevin Drumm, Fred Frith, Jean-Marc Montera, Masayuki Takayanagi, and most notably Keith Rowe of AMM:
Items to use to attack the guitars strings, neck, body, pickups and whatnot:
