[IAmBroom]

The sealant has to be self-setting; it cannot rely on atmosphere to "dry" it, because the side facing the hole will never dry. In order for it to dry, it would have to be air-permeable, so not a good sealant at all.

So, the sealant has to be either a 2-part epoxy (harder to mix and apply), or a UV-cured epoxy. It has to adhere to a vast array of surfaces, since we cannot predict if the next leak will be in aluminum, cracked ceramic, silicone gasket, rubber gasket, plastic.... Anything it outgasses must be extremely inert, so that it doesn't cause a new problem when it reacts with a different surface (the gas on the ISS is never diluted by a giant planetwide reservoir).

Paint is obviously not a two-part epoxy nor a UV-curing epoxy; nor is it guaranteed to have fully inert outgases; finally it is not likely to be adherent to all the possible surfaces.

It's as if the situation requires a robotic diamond drill, and you propose we hit it with a big rock. The big rock won't do.