I just delete ALL my saves to do it but I don't know if it works for you though
Hi, I didn't really give a good explanation you need to go to on your case the Acer(C:) look for the users file, select your user name inside, then look for the appdata after opening that go to the roaming and look for the RenPy inside look for the Lustful Desires file open it and all of your save files will be there including your persistent one, if you erase it from there it's permanent erasure.(I'd use a screenshot to show you but my pc is not taking the fricking screenshot)