How do I delete a save file?
Saved games are stored in SAV files, a file with the same filename as your .RPG file or .RPGdir folder. For example wander.sav for wander.rpg. The save file is located in the same folder as an RPG (or if you are using Linux, and the directory that contains the RPG file is not writeable, the sav file will be stored in ~/.ohrrpgce/gamename/)
You can delete this file to delete your saved games. There's no way to wipe just a single save slot except to save over it.
It is not (yet) possible to delete a save file or save slot with a script.