Try whiffing an overhead and following up with meaty c.lk xx ex.tatsu
They will think the overhead is meaty and block high, then cl.lk will hit them low, and ex.tatsu will connect because they are standing. If they block it low, ex.tatsu will crossup on the other side and hit them on the ass (literally), but you will be open to throws afterward, but can still followup with attacks if timed correctly.
I usually do this setup after an otoshi, because they will either be really close to stun and that extra crossup will stun them, or they will be so scared of ex tatsu hitting them, that they wont react after getting hit that one time.
Sometimes even if they block low they [media=youtube]JZH1N81rhrk#t=2m03s"[/media], for no apparent reason, probably mashing out dp, super, ultra, or throw.
Proper timing after otoshi is walk up to their feet, do a jab, walk up to their hitbox, overhead, c.lk xx ex.tatsu.
Might want to practice cancelling c.lk into ex tatsu also, because otherwise youll get c.lk, s.lk, and it will just make you look like a “jab” masher and the oppenent will just turn on “auto dp turbo-mashing mode”