Almost everything an outsider might want to know about this rite is available in print. It was written down repeatedly between the 1880s and the 1930s, in a period when the ceremonies were illegal, when the people conducting them were under direct pressure from federal agents and mission schools, and when the ethnographers recording them were frequently working with informants who had no authority to speak and who were sometimes paid.
Those circumstances are the reason availability settles nothing. A description obtained under that pressure, published without consent and reprinted ever since, is not evidence that it was ever meant to be public. It is evidence that it was taken. Reproducing it now on the ground that it is already in print compounds the original act instead of excusing it.
The nations concerned have said this in their own words. The Lakota Summit V of June 1993 passed a declaration naming imitation vision quests and sweat ceremonies sold for money by people without standing, and calling on Lakota people to oppose them by public and direct means. Comparable statements have come from other nations since. The objection is consistently to two things at once: to the selling, and to the flattening of distinct ceremonies into a generic offering with the nation's name stripped off the front.
What can be said without difficulty is the shape of the thing and why the shape matters. The rite is not solitary, whatever it looks like from outside. A person is prepared, sent out by someone qualified to send them, and received back; what they bring is interpreted within a community that has the standing to interpret it. Remove the elder, the preparation and the community, keep only the days alone on a hill, and what remains may well be worth doing. It is a different practice and it should be given a different name.
The commercial version generally does not do that. It keeps the name.