I need to dry clean my thick winter jacket in preparation for Canada in the next month.  Does anyone know of a true dry cleaner (not a laundry wash place), preferably near Soi Diana and Soi Buakhao?  Otherwise somewhere fairly close to a baht bus route would be great.

Who knows? There may be. But I wouldn't trust them with a high-quality $400-$600 winter jacket. Why not put it in the washing machine on a gentle cycle, spin dry and hang it up for 2-3 days. I've done it this way with an MEC jacket. Or does the label say Dry Clean Only? I think they used to restrict the early Gortex jackets to dry cleaning long ago.