As a moderator on another forum I can tell you that won't work. By the time spam posts are reported they could have dozens of spam posts posted.
Several years ago on a Sunday morning on that other (general computer issue) forum I noticed a spam post in a heavily used section. I did a quick inquiry and noted that the "member" was new having just joined and had 10 posts. So, I started looking at the posts and deleting the spam posts. After a few minutes, after I had deleted 8 posts, I noted that he still had about 12 posts. So I kept deleting spam posts and after about another few minutes I had deleted a total of 18 spam posts and checked the stats and he had 15 posts. I had caught up with him while he was posting and I was deleting them as fast as the system would allow and he was posting faster than I could delete them. After more than an hour total, I deleted the last of the 58 posts he has posted that morning. I'm not sure if he knew his posts were being deleted right behind him or not. The system has been changed on that forum so that you are limited in the number of posts you can make as a new member in a certain time frame. We also have the ability to subject a member to Moderator Preview for either a specified time or indefinitely so a post is not viewable to anyone who does not have moderator or admin privileges. We also have a special area where deleted posts go (they are not actually deleted, they go to a topic named Purgatory and only moderators and admins can see that topic. But with over 450,000 members things can get a little hectic at times. We have three Member Moderators, although on most days one is usually up at the crack of dawn and keeps things down to a dull roar. About half of our time is spam, the rest is refereeing arguments between members about whose system is best, and members getting out of hand with language. Problems that I have never seen here.
Spamming is the bane of any public forum and most have various techniques to try to keep it at bay. I have actually been surprised at times over the amount of spam that does hit, since this is a single product line forum. But sometimes they think they can sell their stuff to anyone. The mods here keep it very clean.
Remember - the NAS is not a backup plan.
Backup = Good, No Backup = Bad