Ooh, Im going to share a thing I learned that has been life-changing (I feel ABSURD saying that, but when I think about it, it actually has).
Vodka, or even better, Everclear. Essentially, alcohol with the highest alcohol content (which is everclear at, I think 180 proof). It is antibacterial and does not smell, or smells so little that its hard to detect. Here's the back story for how to use:
I have never found a deoderant that eliminates a very faint b.o. smell. Think end of the day, your shirt or armpits have a light smell. Sometimes mine have a much more than slight smell (hormone changes, stress, whatever). I did some research and found that spraying your pits with high proof alcohol eliminates this. I found some deodorant (the brand is E.O. I think) that had alcohol as a first ingredient along with essential oil and came in a 4oz pump bottle. I tried this, it worked better than any deodorant I have ever used in my life, so I bought a big bottle of Everclear at the liquor store, and some essential oil, and made my own.
I told a friend about this who works in theater, and she said "oh, yeah, we spray our costumes with vodka because they are too delicate to wash after every show and the vodka keeps them odorless bc it kills bacteria"
So then I started spraying my pits, and giving the outside of my shirt, in the armpit area a light spritz as well, and my shirts never smell. When I finally wash them after several wears, they might have a very slight smell, but usually not.
My plan for my trip to Europe this summer is to pack some Everclear (I still have a lot left from that original bpttle I bought) in a permissible bottle, some essential oil, and my empty 4oz pump container, and combine when I get there (bc I have traveled with the spray bottle containing the combination and even with carry-on, the air pressure still forced some liquid out).
For what you are describing I will spritz armpits before wearing, and then again after, when clothes are hanging and before packing into your suitcase.