Since armpit stains/deodorant stains are more visible on whites, the first three suggestions here are for getting rid of deodorant stains on predominantly white fabrics.
If you're having trouble with deodorant stains and deodorant crusties on your colors, take a look at the last two suggestions in this column. Take a look around the rest of the article, too, because there's a lot to learn and a lot to consider before you throw away another overpriced Banana Republic undergarment rather than clean it.
Deodorant Stain Removal
* The first thing you might want to try to get rid of armpit stains is a simple spot treatment, like those made by Clorox. Do this immediately after you've come home from either a long day of work or a sweaty day at the gym. Just dab a little on both pits-even if you don't see a stain forming yet-and let it sit for a few minutes.
Then, take that shirt and any other whites that might need laundering and put them in the wash with a little more bleach. Keep in mind that bleach is a fairly corrosive substance, so you'll probably end up wearing your shirts out faster this way. On the upside, however, this is probably the easiest way to prevent deodorant stains and armpit stains from forming on your whites.
* Everyone knows that chlorine bleach is bad for the environment, so if you want to get rid of deodorant stains without killing fish, try hydrogen peroxide. Hydrogen peroxide is sometimes sold as "non-chlorine bleach" and its uses are profound.
In fact, hydrogen peroxide is used by fish culturalists to provide oxygen to small fish, and the FDA has concluded that it's safe to use as an anti-fungal solution for fish and fish eggs. The stuff you want to get is found at your local drugstore, and it's sold in 2-3% solutions.
Just put a couple of teaspoons on the spot, rub it in a little, let it sit, and then throw the fabric in the wash (but only with other whites). Don't mix this stuff with colors. This is not a color safe alternative to bleach.
* If you're a cleaning aficionado, you may want to consider using Boric Acid to get rid of armpit stains. Boric acid, sold in a convenient little box under the brand 20 Mule Team Borax, is another eco-friendly alternative to bleach.
Human beings were using boric acid to clean their garments back when philandering and incestuous gods were the vogue in religion. Make a paste with the powder.
About a tablespoon of boric acid mixed with a little bit of water should be enough to spread over, and work into, the fabric surrounding the pits of one shirt. Let that sit for about half an hour, then brush off any crusties with a scotch pad and throw that shirt in the wash. That should be removing your armpit stains real good.
* If none of these methods so far is getting rid of deodorant stains, you may want to consider trying an Enzymatic Cleaner. This is one technique that can be used on colors as well. Enzymatic cleaners are really wonderful because they use proteins made by living organisms to "digest" any organic material they come into contact with. Your sweat is an organic problem, by the way.
The specific process is actually a biochemical reaction between the proteins and whatever it is that's coming out of your armpits. Usually this kind of thing is used for tough stains like urine, blood, vomit and other more noxious issues.
All you have to do is rub a little of enzymatic cleaner on your shirt, and wait as long as the directions tell you (maybe a little longer). Throw that in the wash when you're done, and you might be surprised to find your armpit stains gone.
Want to know more? You can read more tips on How to get rid of Deodorant Stains, plus information to get rid of practically anything else that ails you - from bad breath to telemarketers to cellulite - at http://www.howtogetridofstuff.com