I briefly posted about this activity right before I went off for the NCSHLA convention. One lovely reader requested that I give more explanation into the activity so here goes nothing! (And, I apologize for not posting a better explanation the first time.)
Like most SLPs, a large portion of my students are male. I have found that they like nothing better than to argue over who is taller or has the biggest muscles even as kindergartners. So I had the brilliant idea as a CFY to start teaching them that /r/ is a heavy sound. They have to make their tongue muscles as strong as they can to lift the heavy sound up. It worked for the most part.
I have a group of first graders this year that are very visual learners (in addition to having some really short attention spans). The concept of actually "lifting" with their arms helped increase their focus, but they would eventually get tired of just pretending to hold a weight.
So I went to my collection of paper towel & toilet paper rolls. I balled up some black paper for each of the ends and covered everything in a nice layer of masking type. I added grey paper to the middle of the bigger "weights" to make it look more realistic. (I couldn't get the little one to cooperate.)
So far it has really captured their interest and they are learning to self-monitor their speech without even realizing it.