Just my 2c worth here - it is quite possible to mistake one spirit for another, I think. I once met a flowing, strange but very noble being in the astral, & later googled to find a picture that would represent his appearance. I found one Adi Da, whose writings, when I investigated further, did not attract me spiritually at all.
But on a later occasion, I came across a photo of Yogananda, in almost the same pose, & realised it was he, not Adi Da, who I had met in the astral, & to whom I had said that I was 'with him" (meaning I agreed with him) "lock, stock, barrel & insence" (at which he chuckled)
I admit that I find Robert Bruce's latest advertising rather disappointing, & put it down to his being poorly advised by some "promoter"; but that does not detract from the fact that he definitely helped me with healing on more than one occasion.
As to the efficiency his techniques, I can personally attest to the fact that they do work; but I also use mantras from the S A Weor school of Gnosticicsm, which also "work"; & so do the totally non-mystical techniques taught by Michael Raduga.
It seems many different means can be used with similar results, & in the end it is a matter of what/who appeals to one's dominant personality structure. I mix & match; no idea whether that is a good or a bad thing, or whether it even matters.
edit: typos