Removing yellow stains

So yesterday when I removed my manicure, I discovered the most unattractive yellow stains on my nails!  I know that this happens, but it's the first time it has happened to me.  Not sure how I made it so long, but I did.

I immediately tried a few things I had read on the web - lemon juice and soaking is dishwashing liquid.  No change.  So today when I went to Walmart I checked to see if they had anything to help and I found a product in the beauty section!  I was quite excited.

Well, perhaps it sounded too good to be true.  After following the instructions, here are my results.

I really don't think there has been any improvement.  Maybe the slightest bit?  Package said to use several times in first week and then once a week afterwards.  I'll try again, but I'm not holding my breath.

What has worked for you to get rid of stains on nails?