Hoping you get some rain,..soon,..good idea about the expandable insulation foam,..as you said the air wasn't getting at it to harden it,..we have a canister of tire inflate for a car wheel,..it has a proper tire nozzle on it so you just release the liquid and the tire inflates,..you are supposed to have the tire repaired soon after but i have left it for six months and its still inflated.
