A sure fire test: Throw the Ouija Board into the lake.
If it floats, it's a witch-burn it!
If it sinks, the gullible will latch onto something else.
Of all the woo subjects on this forum, I think ouija is qualatively different to the myriad of other subjects posted here, and nothing to do with gullibility.
It is also perhaps the most easiest to scientifically scrutinise, even if only to investigate its remarkable ability to tap into the brain's unconscious creative potential. There are many mundane outcomes to ouija sessions, but some can be quite impressive from the creative point of view.
There was an American woman who was an ouija "expert" who wrote a book on the subject, not surprisingly entitled "Ouija". With her long experience, she identified one common characteristic from ouija sessions with a variety of people with different personalities and interests. She said, words to the effect, that when an individual has pre-judged the likely output of a session, or is specifically interested in gaining some kind of targeted information from the "messages", that is usually what they get. In other words, ouija can be all things to all people. If you expect demons, that is what you get. If you are interested in poetry, or history, that is what you get. She had examples of poetry that she claimed came through the board, although it no doubt came from her own head. It was good poetry, although not very good, but nevertheless it was again remarkable for its creativity, that, so we are told, emanated through the planchette, effortlessly.
I say don't knock it until you try it. You can try it with your own controls in place, video cameras etc, very easily and cheaply. It seems to work most times. In the end, whatever the outcome, it will be your experiment, and although it become no more than just part of your own anecdotal experience, at least you may feel sufficiently convinced that it is worthy of peer reviewed scientific evaluation.