We often have bits and chunks of whatâ€™s left (mostly used up) of bars of soap in our soap dishes (sinks, shower, tub etc.) over the years, Iâ€™ve seen rich plant (mostly grass) growth in areas where grey water runs out on to the ground (e.g. mountain cabin). I know that plants like potassium but as for all the other stuff in soap, I don't know.
For example, we often use Irish Spring Aloe and here is a list of all the monkey business in it:
Soap (sodium tallowate, sodium cocoate and/or sodium palm kernelate), Hydrogenated Tallow Acid, Petrolatum, Glycerin, Coconut Acid, Sodium Chloride, Fragrance, Polyquaternium-6, Aloe Barbadensis Leaf Extract, Pentasodium Pentenate, Pentaerythirtyl Tetra-di-t-butiyl Hydroxyhydrodrocinnimate, Titanium Dioxide, Chromium Oxide Greens.
I'm also wondering about Dish Soap (in bottle) etc.
There are some salts and acids in this stuff but I think only in minuscule proportions so they probably wonâ€™t matter.
Does anyone have any ideas e.g. formulas, methods etc. to make fertilizer with leftover soap?