Yeah, it doesn’t clean shit.
Discussion
Are you sure? For me it removed the downloads (but left the episodes showing in my library - playable over WiFi/data but not downloaded to the device).
Try tapping the home button (bottom left) then profile icon (top left) then settings > library and disable auto-downloads. Then also try the “re-sync” button at the bottom. Worth a shot 🫡 
Yeah, those functions do nothing. Still 21.54gb on my phone