I know someone like this; they said deodorant has chemicals that absorb through your skin & effect your thyroid or something like that

. Instead they use some kinda grey looking paste as deodorant:
it's charcoal paste, same as rubbing a piece of charcoal on your pits which means fuck all, the retardation about thyroid is the whole talc powder shit that some places in they fuck up the quantity and cause talc poisoning not to mention some people are retarded and end up inhaling because they use alot of talc powder.
Better than any commercial deodorant, 72h effect.
no, doubly no if you have armpit hair and is doing anything that gets you to sweat, lemon juice is kind of the same as baking soda, you use it to wash yourself, not keep it on, don't mix them on a paste because they will burn your skin even if you use a less lemon juice per baking soda paste recipe.
talc powder is worse because it gets all crusty without help dealing with the odor and you'll learn that it can help pull your hairs in the most painful way possible.
just use cream deodorants, these are meant to be used post shower and won't burn off your skin, preference for antibacterial ones as they are made specifically for combating the odor chemistry wise, i mean you can even look at their composition and compare them to a regular one, way different.
that is if you are going to do anything that will get you to sweat alot, if you are working in a place where you won't sweat much pick by your desired scent, unless you can't afford much in which case go with antibac and shower proper.