Personally I find melatonin to be superior- especially the Natrol slow-elease Melatonin.
Ornithine is going to have different effects dependant upon what conditions a person is dealing with.
For myself, it just gives a hike in blood sugar, and does not make me fall asleep.
Diabetes (type 1) is a tricky disorder. I suspect that the L-ornithine does not have the desired effect on me because of diabetes lowering the body's ability to produce enzymes (in this case protease) to carry the amino acids to where they're needed.
May you have a peaceful and successful liver-flush!