Well guys I got some new info from Clackamas coot. No need to buy silica anymore!
He just emailed this message.
"I figured out how to use soapnuts to emulsify neem so now we can say goodbye to liquid silica products.
I put 1/4 cup soapnuts ground up into a jar with about 24 ounces of hot water. Soaked overnight.
In another jar, I added 1 cup water with
neem oil.
Then I poured in fresh soap nut concentrate, probably 1/4 cup worth into the jar and shook. Instant emulsification however would come loose after a few minutes."