As we saw above, the first stage in washing clothes is soaking them in water, since this soaking gets rid of some of the dirt. Even wetting a small part of an item of clothing is forbidden, because wetting cloth with water or another cleansing liquid is considered Kibus.
The Rishonim disagree whether the prohibition of soaking clothes in water applies even to clothing that is not dirty. According to many Rishonim, it is only forbidden to wet clothing if it is dirty; but if the clothing is clean, one may wet it. Others maintain that one may never wet clothing, because any wetting accomplishes some minimal cleaning. In practice, since this is a disagreement pertaining to a Torah law, many Aĥaronim follow the stringent position, maintaining that even clean clothing may not be wetted.
However, one may wet clothing or any cloth item if this will make it dirty rather than clean. For example, one may use a towel to dry one’s hands, because the water from one’s hands does not clean the towel. On the contrary, it dirties it slightly. Some make a point of first air-drying their hands slightly and only afterward using the towel, so that the towel will absorb less water. In any case, the halakha is that one may wet a cloth in a way that dirties the cloth. This is true even if the towel is already dirty, as long as one’s intention is to dry his hands, not to remove stains (SA and Rema 320:10; BHL s.v. “de-lo”).