If you are asking whether or not such answers should be downvoted, that's entirely up to you. I've never seen a successful meta policy on a StackExchange site that specifies whether or not answers should be downvoted. It is unenforceable. But personally, if an answer doesn't reasonably describe why it would work, and such a thing isn't obvious, then I'd probably downvote it and leave a comment requesting clarification.
However, as mentioned, we need no Meta consensus for that.
If you're instead asking whether such answers should be flagged or deleted, I would state that no, they shouldn't, except possibly in the case of answers that are trolling and actively harmful. For instance, if someone asks How to remove ice from a windshield and I leave an answer that says "Dump a bucket of black paint on it", well, not only does that not explain how it would work, but if someone is foolish enough to attempt it they'll be in for an unpleasant surprise.