I take no credit for this idea, I happily stole it from a WonderTiger member who showed us how well it worked on his trucks.
You get the O-Rings from McMaster-Carr, get the Hard Buna-N compound. It is a lot more durable and will take a beating for much longer than fishing line. No, they aren't indestructable, but they do last a good while.
The part number I use is McMaster Carr part number 5308T311. They fit perfect on my Trencher X's.
I use two on the X's, one on my MT4's tires. (Same size)
If you run a different size tire on your truck, you just need to get a set of calipers and measure the outer diameter, and order a slightly smaller size O-Ring. You want the fit to be snug, but not so tight that it compresses the foams too much.
On my Trencher X's on my ERBE
On my MT4 G3