In the old days soap was made from Lye, or potash because it was widely available and olive oil was not. I had a problem with mine in that they were very difficult to charge and turn on. This review is largely based on that, as I have good sound equipment inside the house. I have bought many plate hangers and these are the worst I?ve ever bought. Now my feet don?t hurt at the end of the day. And obviously quite easy to wash if (when) they get dirty. Birkenstock sizing - solved! Great portable speaker. 34 oz for the pair (that?s 3. We traversed lava tubes & lava fields and waterfalls, explored beaches, snorkeled and walked miles on sidewalks in towns and had not one single problem with these shoes.