No, you take a minute amount of solvent (heptane is said to work best, but naphta does the trick also) warm it up and dissolve your fresh, first draft dmt in it. Subsequently, when it cools the crap drops out first due to solubility issues. You can then decant while making sure the gunk stays in the container. Then freeze precip again and recommence procedure if you wish.

This is a quick mock up of how it goes, check the wiki for the tek in full.