This is a bit shaky; but I think I recall from reading Peter Carroll and Austin Osman Spare that one's supposed to create a sigil, energize it, then put it somewhere you'll never see it again; not perpetually see it. I would expect a double-blind study to find more priming from explicitly visualized concepts than from obfuscated symbols, but it might be interesting to throw that in as another option alongside various vectors for subliminal messages.