Bro, thanks alot for this. I tried this and was in training mode for an hour and watching for that circle enabled me to hit it almost constantly. Major props.
Am I right in assuming the most that can be done is five? I did five and was out of range for the hp seismo to hit.
i did the dragon punch method finishing with up forward
i guess i’ll learn the safe method when i get punished for accidentally super jumping into trouble 
i find it easier to us the forward and up method
Go into training with ex set to refill. Now do a seismo and FADC out of it, like normally using two stocks of meter. The point of the seismo animation where you can FADC out of it is the exact point where you wanna FINISH executing your next seismo. So in other words, seismo, then do :r::d::df: and then hit :uf:+P at the FADC-able frame in the seismo animation. This method works on EX-seismo as well but the timing is a little quicker due to the quicker animation.
Edit: Do this input SMOOTHLY and slowly during the whole seismo animation, just be certain not to hit :uf:+P before the FADC-able frame or you will end up just sj cancelling the seismo. do not srk quickly and wait to hit uf+P. Do it in one smooth deliberate motion for best results.
The way I train these is to put the dummy in the corner, scoot up point blank and then:
LP seismo xx EX seismo xx MP seismo xx EX seismo xx HP seismo xx HP TK feint
this is a good block string to work because it’s airtight meaning the opponent cannot jump between seismos if you alternate between regular and EX seismos. Consecutive seismos are too slow on start up and can be jumped in between.
Edit: Props to MagnetoManiac for the above mentioned string!