I may have already said all this, but it can't hurt to repeat.  I wash my ties BEFORE taking them apart, in my washing machine, on normal wash cycle with cold water and Quilt Soap (or similar mild product).  I also add a splash of Retayne and throw in a sheet of Color Catcher (or similar loose dye-absorbing sheet).  I hang them to dry and only then dismantle them (if they didn't fall apart in the wash).