Having moved down from the White Mountains to 'urban' NY life, I find myself frustrated with the many recycling rules. (Yes, I am a good citizen and always attempt to reuse or recycle)!
I have an easy solution at my house...the pb jars are the special job of lab/shepherd mix! Of course, I don't buy Jif at the value clubs anymore; because they changed the shape of the jar (longer, narrower than before) so she can't get her tongue all the way down there! But the regular 18-oz jars are perfect!
I figured another way to clean the jars after watching Mr. Rogers years ago. I add dry milk and mix it well. The peanut butter sticks to the dry milk wonderfully. Then I add raisins, cheerios, chocolate chips, m&ms, mini marshmallows, peanuts, anything really. Mix well, making sure there is enough peanut butter in it, and then my kids take it in their school lunch. They love doing this, mixing in whatever they prefer.
All I do when the peanut butter jar is empty, I squeeze a drop or two of dishwashing liquid into the jar and then fill the jar with hot water, put the lid back on . Set the jar aside, later I will get the jar, shake it a little, open it , throw the water away, jar is clean. We recyle and this is easy for me. jamish