Hi Bunny, I'm new at making this stuff and am trying to figure out about preservatives. From reading your post, I gathered that I can use Liquapar Optima for both oil-based products (scrubs, butters) as well as water-based products (lotions, creams). The description saids: In aqueous systems, a co-solvent or surfactant may be needed to help solubilize the preservative. what does the following mean? Would truly appreciate any help.