"Replace all metadata" should "purge" the existing metadata. But there is no way to just "purge" metadata in the UI. You'd have to go into the file system and delete files/folders recursively.
Jellyfin 10.10.0 (Docker)
Ubuntu 24.04 LTS
Intel i3 12100
Intel Arc A380
OS drive - SK Hynix P41 1TB
Storage
3x WD Red Pro 6TB CMR in RAIDZ1 (JF Library)