There has to be some options other than sugar pills for the placebo. Niacin that gives a flushing effect. By pill or powder for long or short release respectively. Combine that with something else or a cocktail literally.

Possibly take another drug that gives you a ‘high’ at a dose which has no effect on the condition under test.

Get enough psychedelic and marijuana users at a focus group for a long list of possibly coherent ideas.

I read that they have no way of double blind testing cupping because it is painful and visibly leaves marks on your body.

I would put numbing cream on each participant’s back, put isolation headphones on them, put some pressure on the persons back, and then apply a temporary tattoo with an electronic bandaid that detects if a person removes the bandaid covering the cupping/fake marks.