S.R.
Throw a bucket of water in the toilet before you go to bed at night. That will force most of the water down. I find that liquid dishwasher soap can really take out stains. After you get the water down, squirt a liquid dishwasher soap around the stained area and let it soak overnight, then scrub in the morning. Comet works pretty good too if you make a paste of it and let it sit overnight on the stained area.