Why does soap feel more slippery than Circe?
Alkalinity. One of the raw ingredients used in soap is caustic soda, which is strongly alkaline. Strongly alkaline substances cause the skin to swell slightly which temporarily closes the pores. When pores close the sensation is that the soap is slippery. The slipperiness in soap has nothing to do with foaming, sudsing or cleaning ability. Ordinary household bleach, also strongly alkaline, feels slippery to the skin, yet does not suds or foam.