Foam insert broken - What to do?

Hey guys, just started to mount my rulux wheels on my badlands, and all the tires were fine except one foam insert tore, and it leaves an empty spot in the tire. I e-mailed proline to see if I could get another one, but I dont want to go to the trouble. Could I fill in the holes with cotton balls (Compacted) or some other material that resembels the foam or should I just go with the new inserts?