I figgered it. After trying two different mold relsease materials (2 parts methyl hydrate to 1 part dish soap and 'mold lube') which failed completely, I finally figured out a way to make liquid latex not stick to itself; I sprayed the latex mold with lacquer. In my test sample, it didn't stick at all, not even the teeniest bit. The above picture shows the mold with lacquer, and with the first 'latex pour' after brushing the first coat. Just like it says; pour the latex in, brush out the edges, then drain the excess. Makes it nice and even-like.

If anyone reading this attempts the same thing, I recommend gloss lacquer, so it's easier to tell where you have and haven't lacqered, and thin-ass coats. If it drips, it's all over.