liquid balance

I've been using plastic pellets for balancing.
You can buy them very cheap as ammo for air guns ;)
Centramatics are good, but costly .

Before you go the route of liquid or beads, check out centramatics they work great, they have been used by truckers for years and are also designed for MHs..

http://www.centramatic.com/

I have them on my Harley and love them, they have increased my tire milage greatly and no tire vibration at speeds as high as 105 mph

Don't put that junk in your tires. If you ever get a flat, the repair guys might not do the repair because of the mess inside the tire.