These are some methods I use with references from a site. From mnn:
Baking Soda: This works if you apply it to a dry surface. Over time you may have to have to reapply, but it works. Here is a recipe, but I just use plain baking soda:
Using baking soda as a deodorant is a
simple way to combat body odor without subjecting your pits to a
variety of chemicals. Mix an eighth of a teaspoon of baking soda with
a little bit of water — don't dissolve it — and rub it under your
arms. You can also create a baking soda and cornstarch mix to fight
odor and help prevent wetness. Simply mix one part baking soda with
six parts cornstarch and dust a little on your underarms.
Shaving you underarms: To get rid of the smell, shaving your underarms can work. But in a pinch this tip may be worthless.
Using scented antimicrobial soaps: Soaps such as Tea Tree oil and Peppermint can kill the odour causing bacteria and leave you fresh and clean smelling.
Lemon Juice: This may burn if you have any open wounds. You can even use non-sugar lemonade as a cleansing solution.
The citric acid in lemon juice can kill odor-causing
bacteria, and there are people who swear by the lemon deodorizing
method. Jennifer Palmer, chief executive of an organic skincare line,
told The New York Times that she swipes her armpits with a sliced
lemon on a daily basis. Just be sure not to apply lemon juice to
recently shaven armpits — ouch!
Rubbing Alcohol: All these methods I use and they are cheap. The alcohol may burn if applied to fresh shaven arms or wounds. These include hand sanitizers, but make sure the are healthy before applying them to yourself. These really work in a pinch.
Rubbing alcohol is another inexpensive and easy deodorant that kills
odor-causing bacteria. Simply fill a spray bottle with alcohol and
spritz your underarms with it. You can even add a few drops of your
favorite essential oil to give it a scent — witch hazel absorbs oil
and is mildly astringent, and tea tree oil can help relieve body odor.
Just cleaning really quick works. If you bring some soap you can probably wash up real fast, baby wipes and other cleansing solutions ready work wonders.
Making solutions out of essential oils work, but make sure you aren't allergic. Mixing a peppermint or Tea Tree Oil and water solution works, as well.
Home-made Deodorant recipes:
Tammy Luna's deodorant
1/4 cup baking soda
1/4 cup arrow root powder or corn starch
5 tablespoons coconut oil
Combine baking soda and arrow root powder in a bowl and mix with a
fork. Start with about 4 tablespoons of coconut oil and add it to the
baking soda mixture, working it into a paste. You can store the
deodorant in a small, air-tight container or put it into an empty
deodorant stick dispenser.
Amy Karol's deodorant
3 tablespoons shea butter
3 tablespoons baking soda
2 tablespoons corn starch
2 tablespoons cocoa butter
2 vitamin E oil gel caps (squeeze out the oil)
Melt all the ingredients except the oils and stir. Then mix in the
oils, pour the mixture into a container, and place the container in
the fridge to set. This recipe filled a 1/4 pint jar.
Three DIY antiperspirant alternatives: These are recipes and are all natural and made of cheap items. Because if you don't sweat you won't smell. But make sure you aren't allergic to anything.