DIY Liquid Soap- 2 gallons for $1 Make your own liquid hand soap. What you will need: 3 Bars of Ivory soap 12 Cups of H20 24 Cups of H20 Reserved Grater/Pan/Wisk or Stick Mixer 2 Gallon Container for storage. Grate soap and dissolve in 12 cups of hot on stovetop.Let cool and sit overnight.Whisk soap mixture into 24 cups of water and pour into the 2 gallon container and let sit for 2 weeks to thicken up.*Blog says you can use other types of bar soaps as well. *Add Tea Tree Oil to finished product for antibacterial/to keep it from growing any funk.