Antihistamines don’t stop zika, dengue, chikunyunga, West Nile virus, Japanese encephalitis or malaria. An itchy bite is annoying but not nearly as annoying as foetal defects or bleeding out of all your orifices.
Spraying DEET on your clothes is pointless and will just damage your clothing. It must be sprayed on your skin and rubbed in (meaning it’s useless on a bracelet too. Longer explanation for this below.)
If you have clothing that is impregnated with insect deterrent, it will be with Permethrin. You can top up the permethrin in clothing with spray or wash, but don’t spray this stuff on your skin, it’s really not good for you! It can’t be absorbed though once it’s dry. It does not repel insects - it just kills them once they’ve landed on it (and for this reason it is used on hiking trousers a lot to kill ticks, because Lymes disease is less fun than chemicals too.)
There is absolutely no evidence at all that vitamin b has any useful effect as a mozzie repellent. Plenty of scientific research though that shows it is useless. I can provide a link to these studies for the very determined disbelievers if they want. As I can with all the other things I’m saying here. But the vitamin woo-ers seem to be the ones who rail against chemicals the hardest. 🙄
If you have an urge to not use DEET, picardin, and lemon eucalyptus have been proven to be as effective as DEET. Use the same way as DEET, ie on the skin not on a bracelet.
DEET does not work by smelling bad to insects, mosquitoes can detect it through their feet. Studies have shown that you can be wearing DEET and they will still land on you, but will not bite and fly off again straight away. This also explains why they will bite you through fabric even when wearing repellent. It has also been shown to interrupt the scent receptors that are receptive to the smell of human body scent. So they are not repelled by the scent of it as much as the fact they struggle to smell you as well. Other scent deterrents can also disrupt this smell pathway, but do not have the added benefit of making a mosquito that has landed on a patch of DEET covered skin fly off again. If a mosquito is able to find a bit of skin with no deet on, it will stay and bite. No matter how smelly the deet-y air is around it.
As I’ve said before, I travel for work to many parts of the world rife with tropical diseases. I’m subjected to regular and frequent training courses on how to avoid diseases, and having known colleagues who have died or have suffered very long term effects of insect borne tropical diseases, we take it pretty seriously. But if you want to rely on bracelets, unproven vitamins, and antihistamines to stop the itching, feel free.