Whenever I'm done with a milk carton I squeeze a drop of dish soap into it and add hot water. Put the lid on (often holding the lid down) and give it a really good shake then rinse with cold water and let drain. Only takes a few minutes as I do something else. I give my niece the thread spools since her teacher is heavily into crafts like the spool figures. I gave my niece a note to give to her teacher to see if she needed any recycling things for art/crafts. Teachers as I know there are some on the QB often use their own money for things in their classrooms. I'm willing to help any way I can.