I disagree with the traditional association between N-methyl-tryptoline and MPTP.  In fact, after doing just a bit of research into the source of this "knowledge", I came to the preliminary conclusion that the association has been hyped up without proper factual basis and amounts to nothing more than fear uncertainty and doubt.  There is a thread on N-methyl-tryptoline in the harmalas subforum, titled 2-methyl-1,2,3,4-tetrahydro-beta-carboline and you can find my assement of the rumored neurotoxicity here .  The thread is also mentions the presence of this substance in psychotria viridis.  As far as I know, there is no apparent relation between traditional ayahuasca consumption and Parkinson's disease.

I any case, betacarbolines appear to be highly insoluble in naphtha, so should be easy to clean up.  The above linked thread also mentions it being a minor side product in some Shulgin synthesis and apparently he mentions it being easily removed by recrystallization.

With regard to the hydride that you mention (which I would definitely qualify as non kitchen friendly), there are safer alteratives, like metallic zinc.  Even better, with zinc, it also works in aquatic alkaline conditions.  Pictet-Spengler condensation might be less likely in that situation.

I should remind readers that formaldehyde, even though easily acquired in many locations, is a nasty chemical.  While not nearly as nasty as methyl iodide or dimethyl sulphate, it is still not something to be handled without proper care, equipment and skill.