How about this…
Step 1.
Have the system keep track if you use the same 20+ character phrase more than 3 times in the course of 2 minutes
Step 2.
Once your account is flagged for meeting the threshold of using the same 20+ character phrase more than 3 times in the course of 2 minutes it then either…
A. blocks the user from repeating that phrase again for 5 minutes “You’ve said that too many times”
or
B. The user is allowed to input the phrase but nobody sees it. Basically nobody but the user will see that phrase if repeated too often.
or
C. The user is warned he’s repeated a phrase too often and that subsequent attempts to use that phrase may result in being muted (at first for 3 minutes then 10 then 30+ if they keep doing it
or
D. once a player is flagged as having used a phrase too often they then become vulnerable to MUTING, AFTER a person reports them as a bot,either completely for a duration or where people can’t hear what they say…