I attempted (and I mean attempted) to smoke a razor's edge of my homemade freebase yesterday to no avail. I experienced no effects, ill or otherwise. I prepared a lightbulb vaporizer. I am hopeful that I simply did not smoke enough, but it is possible that I smoked incorrectly, or that my product doesn't contain a high enough content. Right now I have enough mhrb to perform many future extractions, so this is not too much of a concern, but certainly I don't want to waste anything. In your experience, what most likely went wrong?

Note: Is it possible that even though I have a precipitate that mostly resembles freebase, that is not entirely pure?

You probably just didn't vape enough. Vape more but be careful, too much harmaline is a pretty disorienting. I smoke ~200mg a day but that's in around 10 bowls of cannabis or so. By the end of the day I am just melted and sleep is wonderful.