If you believe someone is making posts using Ai then simple report it here (
https://bitcointalk.org/index.php?topic=5456516.0) and move on. And regarding using tools to fix grammars, I personally wouldn't recommend those as they sometimes alters your own words. As a last resort you can only use the basic one, the minimal one that shows mistakes below the words, for example when we write something on the forum's postbox and it shows a little red lines.
You can use Quillbot or Grammarly to fix a few of your grammatically or vocabulary errors, but not to have it write or completely alter your text for you. We want to interact with humans, not AI chat bots, I could do that on ChatGPT if I wanted that.
Stopped using them after they integrated AI in their system. They were better without AI imo...