The reason i looked up this thread is because i found 3 caches that had PB jars as a container. i was really impressed with how dry the contents were, even when the outside of the jar was covered in mud.
i found a plastic lock container and the log book was damp. The PB jars that i found were the big size and held items and a good size log book. i'm just looking for a good container for SW FL, where we get downpours and areas flood easily.
i also like the idea of "reusing" a container instead of buying something new. The PB jars i found were really clean inside. Probably since i'm new, i also liked that i could spot the PB jars red lid. 2 were hidden really well and all i saw was a flash of red!
In any case, it's what i decided to use and i got some good tips such as filling the jar with bleach water. It's fun seeing the different containers folks use. Good to know which are best in specific areas.
The only thing that you have to make sure of doing is to wash out the container thoroughly and you will be alright. If you put a peanut butter jar out in the woods without washing it, it will be found in a day or two by bears or raccoons and your cache will be destroyed, possibly along with the hiding area!