It sucks that your RV was broken into. I wish people had more respect for others property.
If it was mine I would probably clean up everything and try to move on. Depending on the toilet I would either clean it or just pull it and replace it. My trailer user the Thetford Aquamagic IV and those are only around $100 so it wouldn't kill me to replace it.
But in reality you can probably turn on the heater in the RV. Then fill the toilet bowl to the top with water and let it soak for a few hours and flush it. Hit it with a toilet brush and then dump a bunch of antifreeze into the tank and throw the brush away.