I can't explain that either, but I disagree that the exhaust hose has anything to do with it. I replaced my exhaust hose over ten years ago (<3,000 engine hours) only because it was leaking air, not any water. There were exhaust gas residue marks (blackish grunge) in my cockpit locker. But NO water. Don't let that distract you.
Go to Page 3, reply #35 for pictures, text from me is in all pages:
Exhaust Hose Replacement 101 with Pictures:
http://c34.org/bbs/index.php/topic,6760.0.html February 2016 Tech Notes