I've been seeing a lot of people replying with blockquotes in the initial question like this:
Try using Ctrl+Z
I clearly said that
Ctrl+Z does not work
I was just wondering if I should encourage this kinda stuff?
Put yourself into the position of a visitor who has the same problem as you and stumbles across your question on Super User. Now, in order for them to understand whom you're addressing, they would have to read all answers first.
I guess it would make more sense if you simply stated what didn't work, without mentioning a particular user. It's not like they're going to get a notification from your @-mention.
If you want to refer to multiple solutions that were posted as answers, perhaps you could write:
I tried pressing CtrlZ as user @foo suggested, but that didn't work.
You could then comment on the answer of that user in order for them to receive a notification in their inbox.