Professor David Lane can tell you all about the techniques and the gurus that teach them. These techniques are not exclusive to Rawat's group., in fact they are considered 'minor' by some other groups who teach more than the 4 techniques Rawat shows.
Here is the EPO link to Professor Lane.

http://www.ex-premie.org/papers/lane.htm

Also regarding Rawat's brother Satpal, I do know that Ron A. Geaves visited Satpal's ashram in Prem Nagar sometime in the 90s.
Ron Geaves is also a professor who told me that Professor Lane has made an 'academic mistake' regarding Rawat-Maharaji.