I have yet to come across a pouch that was not wet, chewed, leaking, dirty, and full of bugs.

I've found four pouches. Three were new plants so they hadn't been out long enough to count.

The second one was planted July 13, 2014. I found it April 18, 2017. It was raining when I found it; not pouring but not a shower either, just a regular rain. The pouch was under a rock in a low spot next to the road, and 20 feet uphill in the shallow channel leading to a pipe draining water to the stream on the other side of the road.

I took the pouch back to my car. It was totally dry inside the pouch. Even with this, the stamp and logbook were also inside plastic bags. After stamping in, I bagged everything back up and replaced it where I'd found it.

Four pouches isn't much of a count for comparison, but the one I found in the rain serves as a counter-example to your unfortunate experiences.