There's been research that has shown quite reliably that sub-recreational doses of LSD and Mescaline (not combined) can induce incredibly vivid visions that can help a person visualize a problem they've been trying to solve, and in the end, make the problem solving easier if not trivial.

The experiment was done to see if the effects of psychedelics were merely "right-brained" and creativity enhancing, or if they could improve harder more technical cognition as well. It turns out they do improve technical cognition quite drastically.