Thinking that winter was over, I removed the chain from my winter bike and dropped it into a jar of kerosene. My plan was to leave it there until next winter. Then it snowed and I had to get it back out. There was quite a bit of grit left in the jar. I was shocked. Kind of like when you get one of those new vacuum cleaners that lets you see how much dust you're picking up.

On other bikes, I've gone a year or longer without penalty. These days, I have to admit that I clean my chains for aesthetics more than function, because I like how my bikes look with a nice clean chain!