Whatnot ArmRods

I made some armrods out of wire hangers with wooden sponge brush handles for handles. Then I bought a box of insulation supports and used those instead of wire hangers. The problem is that they wobble a lot. Other than that they don't bend very easily they are very durable and light. At first I thought that the wobbling was because the handle was loose but they weren't I reattatched them and regained them and wrapped them with wire and I realized that its not what's causing the problem. Does anyone know how I can put the wobbling to a minimum or what else I could use for arm rods?

I've been reading on this here and elsewhere and the favorite seems to be piano wire as described on this old post by Sean @Swazzle (http://swazzle.com/blogs/2005/11/arm-rods-part-one.html). Swazzle has a link to where he got it, but others have posted that most hobby stores that sell radio control cars etc sell it. I don't know what gauge people buy. Hope this helps.