I don't know much about the US constitution, constitutional rights, and how the courts work, but here in Canada, there's a dude in Vancouver who has opened a mushroom dispensary that is "membership" based and has put his name and face all over with the hopes of having his whole operation be prosecuted so that he can make a defence based on Article 7 of our Charter of Rights provision on the rights to "life, liberty, and security of the person".
This was done with weed when this defence was used to show that scheduling weed was a contradiction of the Controlled Drugs and Substances Act because the purpose of the Act was to protect people's health.
Not allowing people to be treated with weed was therefore seen as a violation of their Charter rights to "life, liberty, and security of the person".
So, he's hoping to have the same thing happen with mushrooms by using his dispensary as a treatment centre for people with ailments generally agreed to be helped by psilocybin mushroom use. He currently only sells micro-dose capsules and the national police force is uninterested in pursuing him at this time. He's hoping to open up more space at the dispensary to have higher dose treatments at some point soon.
So, basically, one gnarly way of doing it might be to attract legal attention to have the laws quashed as unconstitutional.
Should work in any common law country, no? Depends on the judge, I guess. Our judiciary is pretty reasonable and fair, in my personal experience.