Just slip in the skein, pull from the middle, and you are done. No need to roll the yarn into balls. I have used this with my elementary kids with no problems. I wrap the container with contact paper to make it more attractive.
Introducing.... THE GLUE SPONGE! You just cut a sponge to fit in a container, pour glue it, and the kids can just press their little cut-up pieces of paper on it. No more globby glue puddles! What a great idea for kids and adults!