I apologize - I don't remember you asking that. No, I don't teach it. While I'm sure there are ins and outs to doing it well, I've had some students who've told me they play seated once in a while in school, but they never seemed to have any questions about how to do that. Just being completely honest. I've never once told a student I don't think they should play seated, and I've played seated a few times myself, e.g. a rehearsal in someone's band or orchestra room where bass stools were kept. I just put one leg up a on a rung, got comfortable, and that was the end of it. And if a student wanted to sit, and had any difficulties at all with it, I'd suggest they find another teacher.
I'm about to have a few lessons with my own teacher again, who plays seated - I will ask for a primer on the subject, and thank you for the reminder.
-S-