Well call me a dumb @$$, because it only took me 5 months to leave a key fob in my pants pocket and put it through a one and a half hour wash cycle. I thought it was goners and I had blown $300 or so but it came out still working! I then took it apart and dried it in a bag of rice and then in a baggie with some silica desiccant. I didn’t find any visible water in the inner electronics. It seems to be protected by a solid silicone membrane behind the buttons which also forms a gasket to seal the plastic back side around the circuit board. This thing may not be water proof but it’s built to be very, very water resistant. I don’t recommend testing it, but It made it through a washing machine cycle. And if I’m right about water not getting into the electronics, then I shouldn’t have a problem with corrosion in the future. Thank you Honda for a great design. One note if you take it apart and remove the silicone membrane. Be careful, the key covers on the outside that you see are individual and will fall out and be hard to find. (Don’t ask how I know this)
Ken, I want you to know that you are not alone. I have a new data point. This morning I threw my bike jersey in with my laundry and then spent over an hour looking for my fob. hmmm. I would say the fob had been soaking in 30cm of soapy water for about half an hour, then rinsed and squeezed a bit. I towel-dried it, went straight to the car, and opened the door. No rice, no silica desiccant. No problem.
I've had numerous USB sticks go through the laundry. Some more than once - I carry two encrypted drives in my jeans watch pocket - and every one has survived intact. One has been going for 8 years after the initial swim.
I should like to add that not only did my fob come out of the wash without a problem, but the back of the fob is now much shinier and cleaner looking than the back of my wife's...
I admit that I also have washed a Honda key fob. I opened it up, let it dry, put it back together, and it worked fine. I wouldn't make a habit of doing it though.