It's a horrible idea. Beyond the obvious ethical problems with dosing people without their consent, you aren't guaranteed to have a good experience. In fact a positive experience is probably pretty unlikely if you have no idea what's happening to you or why.

Uses of psychedelics to treat depression or PTSD are happening during a counseling session, and has apparently had some promising results. Although I'm not sure if they've used a comparable length counseling sessions as a control.