I wash my kimonos with cold water using liquid soap (powdered soap has a tendency to cling to the material). I hang my them up to dry. If your breaking in a new kimono you can wash it and use brief intervals in the dryer to shrink it to perfection. I have heard that to "set" dark colors you can wash the kimono in vinegar and then follow with a regular wash. I have never tried this so I do not know if its true.