you CAN, if you have friends who you can train with, that you practice the stuff from it
use to do that with Sayoc, but then we would have a seminar ever few months where one of the high ranking guys would come to Az and polish everything up and teach us more
that is how training groups got started, until guys move up in rank for it to be legit
also pretty sure Evan Tanner said he learned BJJ from DVDs (or maybe RIch)
"Eighty percent of success is showing up" James Allen
When in doubt just think...
WWBD™ = What Would Bravo Do