I use the ceramic DynaBeads in my 14-inch trailer tires. They work well.
When I buy new tires, I slice through the sidewalls of the old tires and recover the beads for use in the new tires. I put the beads in through the valve stem after removing the core.
I don't use the special screened cores as I have experienced no problems with just using regular cores.
I use an engraving tool to provide a vibration source when pouring the beads through the valve stems, which is not necessary but does speed up the process. I believe it's a tip explained on their web site.