Cody Don Reeder from Cody’s Lab flushed a toilet using 240 lbs of mercury instead of water. Reeder started by trying to flush a small amount of mercury and scaling up until he replaced the water entirely.
The toilet in the video was built specifically for the experiment and was on a closed system, so there was no contamination.
I see if a little mercury can be flushed down a toilet and then I take the experiment a little farther and flush a toilet with 240 lbs of mercury.
Thanks Scott Devaney!