Yes, you can use Soapnuts to clean wooden floors, but just make sure your mop head, sponge or cloth isn’t too soggy. Using the amphora to make rain water drinkable? Rain water buts are very germy becuase they link into the storm water drains and they can include deadly bacteria such as Legionaires disease. So I would try to collect your rain water in a separate fashion, harvesting it daily. It will then need filtering probably through a charcoal, sand and gravel bed and then boiling and cooling before it goes into the amphora. It would work in an emergency, but it would take a lot of organising on a day to day basis. Also rain water is considered too acidic for the body and it can cause demineralization. The amphora does increase the pH making the water more alkaline, less acidic, so if ever you did have to harvest rain water the amphora would help to turn it into better drinking water.