What solvent if any has anyone had success rinsing their freebase in a buchner to clean it up? Alcohols, non-polars, and acetone obviously won't work and I doubt cold water would do much.

You could wash it with a solution of sodium carbonate but I think the best way to go is to re-x with a non-polar solvent.

dont wash crystals, thats a very innefective way of cleaning because only a small external part of the crystals will actually get washed.. if you want to wash, redissolve the dmt in a non polar solvent and then do a sodium carb wash.

Actually depending on the degree of impurity it might be cleverer to wash with a vacuum filtration device. If the spice is only slightly impure
it will be efficient enough and give a better yield since the sodium carbonate won't have time to dissolve any dmt.

I always recrystallize. I want to do both but there's not much talk on here about washing through vacuum. It conveniently dries it as well.