we have well water which causes my teeth to be stained help!!

something that I could find at wal-mart now. .

I want something that actually works and is easy to use.

After years of abusing my teeth with coffee, tea and tobacco (must be a thing with caffeine and nicotine), my teeth were starting to look pretty bad.   I faithfully visited the dentist every six months for a cleaning (good dental insurance plan) and this helped.   But then, after I retired, the dental insurance was gone and my semi-annual trips for teeth cleaning were curtailed too.
 
Then I moved to the Philippines where, believe it or not, they have a plethora of top- notch dentists available and the going rate for teeth cleaning is only 500 pesos (about ten bucks US).   At those rates, I could easily afford to start going in for cleanings more regularly, and I promised myself I would do that.   Unfortunately, promises made aren’t always promises kept and I haven’t been as diligent as I’d hoped, but I found something else that has helped a little with the yellow teeth thing and I’ll share it here.
 
Grandma knew her stuff in so many ways and the teeth-whitening department was one of them.   Her dazzling smile even into her 70′s was proof positive that she was following her advice and that it worked.   I realize now that I should have paid more attention but then, when the dentist recommended the same regimen I put two and two together and came up with a new habit.
 
She recommended brushing with baking soda and salt, in a mixture with just enough water added to form a paste.   It tastes kind of funky, but then, so does most medicine and that’s no reason not to take it.   Anyway, you can always hold your breath while brushing if the taste is that disagreeable to you.   It’s really not THAT bad.
 
My teeth have become noticeably whiter.   I don’t know WHY it works… it’s enough to just see the results every time I look in the mirror.   Others have noticed too.  
 
I’ve noticed that some of the more popular toothpaste brands are now including baking soda in some of their formulas.   Even Arm and Hammer, the people famous for making the little orange box of baking soda that everyone has in their refrigerator to take away odors, has their own brand of toothpaste too.   This is good confirmation that baking soda really does what Grandma said it does.   I never doubted, it, really.
 
It’s important to bear in mind that baking soda is fairly abrasive (especially when salt is added), so it’s not something you want to use everyday.   I do it once a week, and that seems fine.   I don’t want to dissolve all the enamel on my teeth, so I’m careful not to overdo it.   Try it out.   It works.