I agree with vancoder's approach on this one. What Chip Bennett is calling "feeling" out an answer or "vetting" an answer, I would call "debugging". If it is a guess, it is not an answer; it is an experiment intended to gather information. If the comment leads to a solution, or turns out to be a solution, it can be added, perhaps in more detail, to an actual answer and the comment deleted.
I understand the concern about cluttered comments, but the alternative is cluttered answers. Since, it is reasonable, I think, to consider answers as having more of an authority to them than comments, I would say it is better to have extra comments that (rarely) get cleaned up than extra answers that (rarely) get cleaned up.
Clarification: I have no issue with the basic idea that answers should be posted in the answer box. I suggest exactly that very frequently when reviewing items. I dispute Chip Bennett's interpretation of this comment thread and by extension similar threads. I dispute that this sort of comment constitutes an "answer". Furthermore, forcing this kind of thing into the answer box will create more mess than it cleans up.