You can use any reciepe for BrineSoap. First soap ever made in 13hundredsomething was a BrineSoap made with seawater 3% salt Just add max 20% salt (of the water amount not PPO). Dissolve salt in hot water, let cool, dissolve NaOH, and do as usual. Store in very dry place. I've made BrineSoaps with 3, 5, 10, 15 & 20% salt of water. 20% is a little too high for me, 10% is betst for my sensitive skin.