You could pay someone to help filter website spam but you will get false positives. Or you could just use the default WordPress blacklist option built into the options that nobody thinks to use.

Automatic

• Install plugin, activate and let it auto sync the blacklist from github.
  • https://wordpress.org/plugins/comment-blacklist-updater/
• Install another plugin, either Antispam Bee or Akismet.

Manual Results

1. WP Admin
2. Settings
3. Discussion
4. Disallowed Comment Keys
5. Let’s CTRL + A and than CTRL + V the WordPress Comment Blacklist text into the “Disallowed Comment Keys” area of your website.
6. Install Antispam Bee or Akismet

Why is this a good way to block wordpress comment spam?

• It’s not annoying. No additional friction for user engagement.
• No false positives. Automated plugins stop anybody trying to share multiple links. The blacklist option does not prevent anyone except those using certain words.