Originally Posted by
Aus_Mal
Your passport will now be treated as very suspicious by most immigration agents who see it. "Washing" passports can be used to help hide changes to the data pages or to remove stamps that you would prefer that immigration doesn't see.
Best you get it replaced (the passport, not your Mother!)
I second this comment. I've gotten strange looks with a passport that got hit with a little rain. Better safe than sorry. Get it replaced.