Foam Insert Cutting/Firmness tricks for oval

[z28mccrory]

Im curious what everyone does for their foam inserts for oval. I always just trimmed the edges to take off the sharp corner on the outside.

A buddy let me try some tires that had worn out foam in them and they worked 10x better than the white foams that came with my Pro-Line and losi tires. The tires were square fuzzies that were extremely worn down with foams that were so soft that the tire was about halfway to the rim when you sit it down. They provided a TON more traction that my new of the of box square fuzzies with regular foams.

Whats a good cutting technique to achieve this super soft "worn out" feel. Im mainly refering to 1/10th truck tires/foams... but buggy stuff would also be interesting to discuss.