"Airsoft "plastic BBs work just as well as the Dyna beads and cost less they might even be the beginnings of Dyna beads. Off roaders started using the BBs in big floatation tires years ago with very good results. For regular sized car tires you just measure out 3.5 oz. of Airsoft plastic beads and toss them into the tire through a broken bead or while mounting the tire for the first time.You can buy Airsoft BBs in the sporting good section of your favorite department store or most sporting good stores it's about 12$ for a big container that will do about a dozen tires. Once you use the BBs you can not use any type of tire sealer like Slime or Fix A Flat.