How Does Spongebob Take A Bath Underwater?

Spongebob taking a bath underwater

Well for first, Spongebob is a talking sponge that is living underwater in a big pineapple with a snail named gary that meows and you're worried about his bathes?!

Also odd how Spongebob expands in size when he gets wet... even though he's in water.

But still funny.