It should harden like old paint. A couple of years ago, I was dying traps and had to cut it short before putting everything away. I just covered the bucket and set it in a corner. The lid didn't fit tightly, and I forgot about it for a few months. The volume was well down into the bucket, and the stuff in the bottom was pretty gooey. I put it out in direct sunlight for a couple days, and it dried right up.
