Oh no, that was long before the spammer decided to stop. But you've already made up your mind against word muting. You don’t need to take my word for it—just check the posts from that time.
If you want to keep pursuing sophisticated anti-spam strategies, go ahead. Just remember: sometimes simple solutions are the most effective. And don’t chase theoretical “optimal” solutions that end up useless because they’re too complex for the average user to apply.
Occam’s razor still applies. Look at what works in practice.