I'll assume you mean not washable...since humans are 80% water submersing us doesn't really hurt us much...unless you get water in your lungs water can't really hurt you....
If we weren't washable, it probably wouldn't matter much.
We'd all just smell more, but since we'd all smell we wouldn't notice it.
I think amore interesting question would be, how would we write if we hadn't evolved with opposable thumbs?