iPhone 5SE Exposed to water

Depends on what you need out of it. Obviously water got in, and in any case Apple never even claimed that the SE was ever water resistant. Even if it were, Apple's disclaimers that they won't cover liquid damage are solid. And I'm guessing it's out of warranty anyways unless it's one of the last ones Apple sold before discontinuing them.

Yes - it might be possible to get it working again, but really only in order to do data recovery. Rice really does nothing and can even make things worse if wet rice dust dries out. I don't know where this myth started or why it's so commonly done. Maybe a real silica gel desiccant can do something but even then it's fairly limited. If you're lucky then a few of the surface mount cap/resistors either shorted or opened and can be replaced by someone skilled in that kind of work. It would have to be cleaned of any corrosion and any damaged parts would need to be replaced. And if you choose that sort of repair, Apple won't typically do their replacement service if you bring it in.

It has been destroyed by the water.

Apple will not even attempt any repair and the device must be replaced.