Underlay foam
From AmtWiki
A good substitute to "Fun noodle" is floor underlay foam, you can purchase it in any hardware store, in the flooring department area. standard prices are $25-$60 for 100 sq ft rolls, I recommend the Roberts brand.
Wrapping the foam around till you have the thickness needed to pass RoP standards. (2.5") use of this type foam reduces the wear and tear issue of "tipping" and "core blow outs", but does weigh slightly more than a noodle sword.
