Marbe,
As per Rav Belsky, if I remember correct, its a factual and lomdot question; he agrees that “some” indeed shave their hair as an “offer per se”, but he claims that according to all Hindu priests it is a concept of self-sacrifice only – NOT Takrovas, and therefore, what each individual does is considered “shlo kederech Avodah” and permitted. Rav Elyashov, I think, never responded on that point.