Originally Posted by Schmorgy
Fret a note, thumb slap it, then slam the other three fingers on your hand to the fret board to make a muffled slap akin to a ghost note. Then just leave your pinky where you want to pop (probably the octave from your slap) and pop it. Repeat until you can do it faster and faster and then you can just mix up the order from there.
It sounds a bit like wooten's double thump technique with his thumb, and acts as a decent alternative to it until you can actually do it.
+1, you could also try going a little bezerk on your bass until you hear what you're going for. I stumbled across something very close to the above through experimenting.
For redefine, I believe most of the action is muted notes, at least that is how i hear it, so it is a bit more of a rhythmic thing as opposed to playing a bunch of notes.
Hope this helps...