I can see this ending up as an "oils aint oils" thread.
There is a lot of discussion on the forums debating the merits of Dynabeads, but in my own experience, they work, even on gravel roads.
Dyna Beads dynamically balance tires on the move, resulting in a smoother ride, and one that lasts the life of the tire, and you can transfer them to the new tyre.
Dyna Beads are small ceramic spheres, high in density and perfectly smooth, that travel inside the tire to locate themselves opposite heavy points to eliminate out-of-balance motion.
I got mine in Perth from - Guy Gudgeon,
aafrasta@bigpond.net.au
about $35 delivered.