Watch the Palm Punches online guitar lesson by Chris Buono from 60 Electric Guitar Techniques You MUST Know
An alternative to scratching/chanking is a percussive technique I call palm punching. As the name implies you are doing just that – making contact with the strings with your knuckles. In essence, you're punching the strings. While the minus, at first, is some jacked up knuckles, the major plus is the ability to play more precise ideas.
Looking for inspiration? It's all here: Funk Fission
. Where did I get mine? Wayne Krantz.