foaming soap
So, here's the deal. Once you use up the original container, you open it, pour in maybe a 1/2 inch of liquid soap (buy the biggest container you can of that so you are buying the least number of consumable plastic bottles) and then fill the rest with tap water. There you have it, handy and identically foaming soap. I use Dawn blue soap for dishes and Dr. Bronner's castile (almond and peppermint are my two favorites) for hand soap in the bathroom.