DCM is heavier than water, xylene is lighter than water. I dont know how that works out, maybe they will separate in two layers (+ the water layer) once you mix it with water? I wouldnt use such a mix. Also DMT and impurities are way too soluble in either of those two solvents so even if you had just one of them pure, it still wouldnt work for re-x (but it would for pulling a crude mixture which you could later purify with another solvent or other methods discussed in this forum)