I've read somewhere that it's easier to maintain the creme method if you cover the covered areas with plastic wrap which keeps it from drying out. I personally will prefer the submerge in liquid method. It will likely coast a bit more in material (like finding and buying a clear plastic tub large enough for my Macintosh SE or SE/30 when I have one). So I've decided the submerge in liquid method to be the safest route for me.