Can a person further dilute liquid soap on shabbos in order to fullfill the opionions that liquid soap should be more liquidy or does it make a difference if perhaps he might like the soap more liquidy to begin with?
Many are lenient with regard to using liquid soap on Shabbos (see Shemiras Shabbos Kehilchasa 14:16). However, Iggros Moshe (Orach Chaim 1:113) was stringent, out of concern for the prohibition of memare’ach. Although the general custom is to be lenient, one who wishes to be stringent should dilute the soap. This should preferably be done before Shabbos, to avoid any concern of molid, turning a solid into a liquid (this would depend on how thick the liquid soap is).