I recently tried EQUAL in a set of bias-ply TSLs. It works best once you get rolling along above 30MPH. I was able to run at +50MPH with almost no vibrations.
You just have the proper size bag thrown into the tire while it's being mounted. The bag breaks apart while flipping around inside the tire and distributes the powder. The bags come with special valve-cores.
If you already have your tires mounted then it's a bit harder; you have to find a shop that has the equipment that blows the material in.