To worry about pesticides in this case is going a bit far - this stuff goes through a refinement process that would denature anythign dangerous, and you only eat about 2 tablespoons a day. Beware of extremisms! They often send you off to even more destructive paths than what they warn against.
You can get choline supplements, which are more like vitamins, one of the main active ingredients in lecithin. So that would be more purified, I think it's an oil pill.