Any tips on softening canvas belts?

United States
July 25, 2007 10:13pm CST
I make bottle cap belts by sewing bottle caps onto canvas Army belts. However, my fiance got me the latest batch, and they are brand new, which means they are really stiff and almost impossible to get a needle through. I know that it's possible to soften up canvas, but putting these belts through the washing machine doesn't seem to have helped much. Any tips on quick and easy ways to soften up canvas belts? Unfortunately, I can't run them through the dryer, because they have metal on one end (which I can't remove), and they make WAY too much noise in the dryer.