Practice doing two consecutive wavedashes in a row (236~236) or (214~214). Then practice doing that out of a buffer, like during the recovery of a 2A (you have to input late). Once you got that down, practice doing three. After you get the hang of that, it should be pretty simple.
Also, you will get better results if you do this with the Chobits song playing.
I have never considered myself Top Setsuka. I am still learning new things and learning matchups. I am confident, however, that when I am really focused, I can do some serious damage. That said, I am fortunate to have some of the best players in the country as my usual play group.