The tub n tile test - I found an old nasty penny and dipped the end in tub n tile for 5 seconds.. before and after pictures..
and here is a soda stain from before I met nick, over 2 years ago. I have tried every stain cleaning, spot treatment out there. I have tried shampooing it and steam cleaning it. NOTHING has touched it even a tiny bit. So, of course it isn't completely gone but what the Sol U Mel did in 5 minutes, I was VERY impressed.