Perhaps instead of a placebo, try a healing ritual or some form of alternative medicine. You can easily have someone else administer the treatment, and you can

Perhaps instead of a placebo, try a healing ritual or some form of alternative medicine. You can easily have someone else administer the treatment, and you can even choose something like acupuncture where there is potentially some evidence that it actually works (I don't believe it but if you can convince yourself, all the better for the placebo effect).