I have used a product called ride-on. in my motorcyle and utility trailer. Learned about it from a family memeber that user to drive big rigs. Seems to work well plus it add a sealer.
We have the Equal in our 35' GT. Seems to be fine but make sure they use the specified valve stem. The sand can get into the stem when you check air pressure and cause it to leak.
Since we bought used, we had never heard of it until we had a flat on a dual from the leaky core. Fortunately, we did not damage the tire. The shop replaced the core and all is well.