It looks like you have a nice well draining mix. Make sure he gets as many hours of sun as you can give him.
There isn't ever a need to wash plant roots with soap. In the future, if you have root rot, you can always take a cutting from the end and re- root it. Which is what I suggest you do with the ones that are bare towards the end. Snip the end off, with a little stem, let it callus over for a couple days, and then pop it in with the rest.
He currently has very few roots to supply water. Your job right now is to water thoroughly when he needs it. By that I mean, take him to the sink, and water until it comes out the bottom. Not just a couple drops trickling out. In the future, using one or both methods of checking (weight or your finger), determine if he needs to be watered.