A good spraying of freon could be helpful in removing any remaining tomato residue and all the dried up conductive minerals left behind from the water and possible residual toothpaste. I'm not sure where you can get ahold of a spray can of that anymore! You can get a non-spraying can from the automotive department intended to refill air conditioners, but I don't know how you could spray that.

Freon is extremely harmful to the ozone layer; that's why you can't buy it in spray can form anymore.

I don't know what else you could do to remove those minerals. It's also quite possible that you've already burned something by trying to turn it on so cleaning it now may not even work.