goodgoalie, don't know if you saw my comment on the music thread the other day, but you keep your hands off Dizzi the washboard player, I've been in love with her for about 5 years now. ;0))
(sorry jubo).
Actually, I've watched that video many times and I'm absolutely convinced there is someone else providing additional percussion - all we can hear is not just coming from her washboard. Right at the start there's some percussion we can hear before she touches her washboard. Odd.