rasgueados are only one group of tricks up a flamencan guitarists sleeve other such tricks include alapuaza etc.
Rasgueados are not commonly used in classical guitar and even more scarcely seen in anything with an electric guitar, and as such it is hard to find someone who has considerable skill to play a competent rasgeuado and harder still to find someone who can also teach to play a competent rasgueado.
i myself about a week ago struggled to play a crap rasgueado... but now with the help of this book i found on the internet i can play an ok-ish rasgueado... nothing to boast about, but just testament to the book (title: Rasgueados are for everyone)...
the link for it is below (pdf, about 50 pages)
please let me know how all of those who try the techniques detailed in the book progress over time
Good luck and dont forget "rasgueados are for everyone"