Nothing is impossible.
Vic's primary technique is (as you mentioned) "double thump" or double thumb. Slap a note but instead of bouncing off the string go
through it then come back up with your thumb to pluck it again.
I recommend getting the DVD "Victor Wooten:live at bass day '98" He goes over double thumb pretty extensively in it. He also is very proficient at tapping and fingerstyle playing, which he talks about on the DVD as well.
Vic's basses have VERY low action and he uses VERY light gauge strings(.040-.090), but that doesn't mean you can't do what he does with High action and heavy strings
Don't get discouraged because it sounds impossible, I never thought I would ever learn "classical thump" but after plugging away at it for a coupel weeks I now have it down pretty well(good enough for me
some webpages of interest:
Some of vic's tech. and ideas:
http://www.victorwooten.com/lessons.htm
This guy has videos of double thumb, and stringed triplets:
http://www.welcome.to/vadimhandmadebasses
Live at Bass Day dvd(to purchase):
http://www.amazon.com/exec/obidos/tg...44842?v=glance
Live at Bass Day DVD transcriptions:
http://www.hudsonmusic.com/transcripsWootBD98.html
Hope this helps some, Also you may want to do a search on this forum, as the topic has been discussed before.
Welcome to talkbass!
hope you enjoy
-Wr