I think you can say that just as
우리는 젖었어요.
우리 모두 젖었어요. (We all got wet)
우리가 젖어 있어요 is also fine though,
it would be more natural on being used when it's the reason of your excuses.
For example,
A: 이리 와서 의자에 좀 앉아요.
Come here and sit down on the chair please.
B: 제가 젖어 있어요.
I'm wet. (So your chair will be wet if I sit on)
And yes, Austin.
That's kinda slang of that expression.
내 핸드폰 물먹어서 고장났어.
My cellphone has broken by drowning.
But if you say that for people then its meaning would be changed a bit.
우리가 물 먹었어.
We've been screwed up.
그 자식이 나를 물 먹인거 같아.
I think that bastard cheated me.
