Well, baking soda works better than toothpaste and cost basically nothing, thats an obvious example.
You have to read about basic components and what they have been traditionally used for (you'll find that many cultures use them for the same things). Then you combine the ones that are said to work and see how well it works, or you can use them individually to get a feel for the effect. Most people are so up their own ass, they wont believe any observed effect is real, like they can't trust themselves and if they notice something positive it scares them into writing it off as "placebo effect" so they don't have to think about it anymore. What a bunch of idiots- they quit before even that usually.
But how placebo can it be if you dont talk about it and strangers and co-workers are commenting, complimenting the effects despite not knowing that you're using anything? That should be proof for anyone.
PM me if you want advice.