You have raised a question which concerns millions but you were brave to put it in writing. An article will be published which will answer your question in more detail. I have already submitted the article. Here is an extract from it.
The Third and Final Choice: This is really the best method as it will work effectively and immediately irrespective of the initial sweaty or smelly armpit. After having a shower or bath, apply an antiperspirant and a deodorant to your both your armpits. Two images of antiperspirants are given in the article. This combination has two modes of action. The antiperspirant shuts down sweat glands this reduces bacterial count and the amount of decaying smell. The deodourant masks any smell there may be, even if psychological.
I cannot place the article here because then it becomes ineligible for publication.
The full article called, "How to manage armpit odour" can be read here.
http://healthmad.com/health/how-to-manag…