I've completely remade the plugin, adding new features and cleaning up so much code.
NEW: You can now configure much more per potion, such as having splash disabled but drinking enabled.
NEW: You can now disable potions being dispensed from a dispenser.
NEW: You can now specify which gamemodes potions will be disabled in.
NEW: Added new error messages, which can be configured.
NEW: Added version compatibility, the plugin should work with all versions and future versions even if new potions are added.
NEW: Removed /disablepotions reload, you no longer need to reload the config, it will update live to the server as soon as you save the config after editing.