I have never seen this, but if my players came up with it I would allow it and flavor it as trying to shock the downed character into consciousness using a dangerous form of magic defibrillation.
My D&D is usually played in a pseudo-Medieval fantasy world, where the characters don't know what fibrillation is, much less how to defibrillate.
Moreover, the characters don't know from saving throws, or the exact rules around death saves. The saving throw does not exist in the fiction, so the character's can't reference making the saving throw happen as a reason to take the action.
So, they'd have to have a in-game, in-fiction reason to think this would work, or it is not a suitable declaration of an action.