There is a way to modify the ACL even if you don't have access to it and the enforce a consistent ACL is turned on.
1. Start the admin client on the server
2. Change the server to local
3. In the files view, select a database that has an ACL similar to what you want (or at least pick one that lists you as an admin)
4. Copy its ACL
5. Select the database that you are locked out of
6. Paste the ACL
That's all there is to it!
Of course, the ACL log is also copied over so it's inaccurate. That's a small price to pay for getting yourself out of a jam.