The "test-content-erase" command:

Usage: fossil test-content-erase RID ....

Remove all traces of one or more artifacts from the local repository.

WARNING: This command destroys data and can cause you to lose work. Make sure you have a backup copy before using this command!

WARNING: You must run "fossil rebuild" after this command to rebuild the metadata.

Note that the arguments are the integer raw RID values from the BLOB table, not artifact hashes or labels.