@cryptoethic As @pitaj has said, this is in our backlog, so it is not available at present.
If you need a solution immediately, you can scrub the entire edit history for that post. Delete the key post:<pid>:diffs and all keys that start with diff:<pid>
e.g. redis-cli keys diff:123.* | xargs redis-cli DEL
Nobody's done so.
In fact, this was a feature requested eons ago! gh#149
Let me know if you find a nice library to handle diffs 🙂