Pretty self explanatory, i just keep spamming left click and the waves keep on coming. Possibly similar to the bug that just got patched on Black Greatsword?
Also applies to the Hero's Sword and possibly more weapons as well.
Doesn't seem to affect all "on Charge Attack" Melee Mods in general however, e.g. the Assassin's Dagger only applies bleed on actual charge attacks as intended.