I thought of this while sleeping last night...
I may have though of a naturally occuring fermcap that grows in our yard for a good portion of the year. Dandelions have white sap caused by high latex content (certain dandelion species are even grown for latex production in areas rubber trees can't survive).
Latex and silicone are fairly similar, silicone being synthetic and latex natural. So is there any reason you could pick a dandelion flower, spray with star san then squeeze a few drops into your boil or fermentor?