You watch those DIY guides be region blocked to "everywhere but the USA" because the fines for even publishing the design of an unapproved medical device are massive.
The US specialized in medical quackery for a hundred years, so there are direct restrictions on speech around claiming medical benefits. The free speech laws permit that, as IIRC societal welfare trumps your right to claim that (for example) mercury and cocaine soda will cure all ills.
EDIT: Commenters are right, you have to try to profit to be prosecuted. If you give away poison and call it a cure, as long as you have no benefit whatsoever, you're technically safe. Yippee.
It is perfectly legal to publicly claim that mercury and cocaine soda will cure all ills. You can post a video or shout it on a street corner or whatever. This is 1st Amendment protected free speech as affirmed case law.
What isn't legal is selling a product and making false or unverified claims about medical benefits.
Just disclaim it with "this device/supplement/lifestyle has not been shown and is not intended to treat any medical ailment" like all the homeopathic crap out there does and you should be good to go.
Agreed. And also add, "may have the unintended side effect of alleviating tinnitus symptoms. These statements have not been reviewed by the FDA. Wash device before applying to the skull."
