If they know which microbes are not attractive to mosquitoes, they can culture the microbes (like making yogurt), and sell it as a topical application.
If anyone finds this product available, please let us Freppers know about it.
Easier to just buy a bottle of tea tree oil and use a tablespoon ful with a cup of rubbing alcohol, to spray your clothing and you ... Mosquitos might even leave your neighborhood with that strategy. Add a tea spoon of lavender oil or Eucalyptus and you have a nice carpet spray to treat your whole house inside. BTW, spray the bedding with the mix and the mattress cover when you change sheets. Works like magic.