Sea Cucumbers used to tame guardians

Sea cucumbers currently have literally zero use. (Or at least I have never used them--and I've spent hundreds of hours mining a big square so I would know).

Guardians also currently have no use because they are just there as enemies to the ocean monument--but once one has been there, they serve no purpose.

To get two birds with one stone, I suggest that once the elder guardians of an ocean monument have been killed, they have the capacity to 'switch allegiance', if given sea cucumbers.

Obviously very barebones and would need some fine-tuning, but something along these lines would be great.

(Also I just happen to have good idea on this date--this isn't Aprils' fools)