Self-answers are generally encouraged here, as it builds up a knowledge database. But I would disagree with @AviDs answer.
Building a knowledge database doesn't seem to be your intention. What you really seem to want is to know if X is true, which is clearly a question, not an answer.
Pro your idea
The only downside I see of making it a question is that if you are indeed correct, it is unlikely that someone will post an answer that basically just says "you are right", which would then mean that the amount of unanswered questions increases. The solution to that would be to hope that someone just posts that, maybe underlined with some sources or further explanation.
Contra your idea
The downside of posting your own maybe false answer is that you aren't actually sure about it. People unknowingly post wrong answers all the time, but I don't think it's ideal to knowingly post answers that may very well be wrong. It adds unnecessary noise, and may mislead people. And what if nobody contradicts you, even though you are wrong? On QnA sites, it is expected that answers are true as far as the person posting them is concerned.
So at a minimum, you would need to add a disclaimer to your answer, eg "I have serious doubt in the correctness of this answer, and I am primarily posting it to get feedback on by though process". But such a disclaimer really only shows that this is a question, not an answer.
Additionally, the QnA format isn't really build for this. Downvoting costs points, the character limit on comments is quite restrictive, deleted comments can't be seen, comments can't be edited, and so on.
tl;dr Answers shouldn't be used to post questions as it doesn't fit the QnA format or this sites mechanisms. "Is X correct" is a perfectly valid question, but "X, maybe? please comment" is not a good answer.