It’s about managing your microbiome to outcompete malodorous species with those producing more favorable odors. If your armpits stink, try resetting your microbiome with an iodine rinse such as Betadine for a few days and you should be fine without underarm products provided you are in good health:
“… an increase in bacteria that compete with odour-generating bacteria may provide a means to reduce body odours without significantly affecting overall microbiota abundance, bypassing the need to use antiperspirants or bactericidal substances.” Reference: …biomedcentral.com/…/s40168-014-0064-3
Additional steps which you can take to improve your microbiome and reduce your negative armpit smell are to minimize your meat intake and facilitate mucus in your digestive tract by taking turmeric and black pepper supplements.