There is no single product or treatment that you can use to tackle stinky armpits. In order to solve the problem, you will need a few lifestyle changes in addition to simply applying a deodorant or some other natural substitute.
First of all, you should be aware that antiperspirants are not the solution. Stopping your body from sweating is in itself harmful, besides which the chemicals that are used in antiperspirants tend to cause a number of other health problems. Deodorants are safe (the difference is that deodorants aim at reducing body odor and replacing it with a pleasant odor) and can be used, but some products combine the two, so you should be careful and aware of what you are buying.
As mentioned before however, simple spraying deodorant on your armpits several times a day is not enough. Your hygiene levels need to be improved - the unpleasant smell from your armpits is due to the presence of bacteria, and is the direct result of these bacteria breaking down your bodily secretions. That you have a body odor problem indicates that there is a considerable build up of bacteria in your armpit area. You should bathe more often - even if you already bathe twice a day, try to get in another shower if possible, at least a quick one that concentrates on your armpits. Each time you bathe, make sure that you scrub your armpits well, and then dry them thoroughly before you dress. The scrubbing should get rid of almost all bacteria, and thoroughly drying your armpits will avoid giving any remaining bacteria a pleasant, moist environment to grow in. After you bathe, you can also apply alum (either ammonium alum or potassium alum) to your armpits. Alum has astringent and antiseptic qualities, and will therefore help get rid of bacteria and also reduce sweating to some extent.
If the climate is hot and humid and you tend to sweat a lot, there is not very much that you can do about it, except for wearing light cotton clothes as far as possible. This will reduce sweating and also let your armpits dry instead of staying damp through the day.
You might also want to look into your diet, and see whether changes such as reducing spices or oils reduce your body odor. The main cause of body odor is bacteria, but certain foods tend to actually make the sweat itself smell, of which garlic is the most notorious.
answered by G M