[@ladyonyx04] Lexi couldn't be swapped because of the water, so it was taken into consideration. If the water evaporated then that protection would go away; looking at the wiki it's actually any kind of water that causes a Devil Fruit user to lose their powers, not just salt water, i.e. it's the water not the salt that matters.

There's a lot more to that weakness than I thought. Moving water like rain or waves won't have any effect, but standing water of any kind will. Devil Fruit uses with more than half their bodies submerged will lose their strength but having any amount of their body in contact with standing water will cause them to lose their powers, unless the properties of their bodies have been changed by the Devil Fruit in some way.