glee is a bulk delete tool that I created. It's very simple to use. To get started, go to line 236 in the code and insert your token. Then, run the file using the command line or any Python-compatible environment.
Be sure to open the setup file afterward to download all the required libraries.
If you need assistance, feel free to create an "issue" or a similar request on GitHub.
Note that the process may take some time, depending on how long it has been since you last sent a message and how active the chat or DM is. This is because it needs to fetch your messages from the chat.