In the course of analysing flags, we've discovered that "Very-Low Quality" means wildly different things to different people. The flag is intended for unsalvagable posts such as:
woop woop woop woop woop woop woop woop woop!
For reference (since they are deleted), the answers called out in the question are:
I think when hermione cast the spell on her parents (obliviate) her memory of her parents had been taken from her so if she lives she won't remember her parents so she won't have to live though the pain of knowing her parents will never remember her
Elves are neither good nor bad. They play by their own rules.
These are garden-variety unsupported answers. If anybody cared, both answers could theoretically be fixed with some additional evidence and arguments. (Additionally, the first has grammar issues.) Assuming you don't want to edit, the best course of action is to downvote. That sends a clear signal to both the reader and the author of the answer that something is lacking.
Both answers also got comments suggesting that the author find some evidence to support their theories. Commenting is commendable when an answer can be fixed. Most people won't bother if the answers are just junk. Truly low-quality posts rarely make it a week on Stack Exchange sites*, which is the primary reason the VLQ flag has been restricted to new posts.
Finally, both examples provided were subjected to previous reviews. One passed the low-quality queue and the other passed the first post and late answer queues. More indicative of very-low quality posts would be a near unanimous consensus that they are irredeemable.
The two examples given aren't examples of VLQ posts. But for the sake of argument (and to be able to answer the question), suppose they were. If you do run across a post that truly stinks and nothing has been done about it for 7 days or more, any one of the proposed actions seems reasonable. None of them work quite in the way the VLQ flag does, but the difference in terms of the end result (what readers see) should be minimal. Either the answer is deleted or has a low score.
* The example I gave lasted 22 minutes.