good for you, breastfeeding your baby will give him what he needs when he gets sick and will help him fight off illness.  i experienced this with my daughter and i cried seeing her gag.  i found an older pharmicist who was willing to play around with the salt till he flavored it.  he happened to make it marshmallow.  most pharmacies will flavor medicines but wont do the salt.  keep calling different pharmacies.  i would pump 4 to 6 ounces a day and i would put the 4ml dose into 1 once of breastmilk at a time.  i would give her this right before her feeding.  if you cant get it flavored try 2 ounces of formula with the salt before  the feeding.  Or substitute 1 breastfeeding with a formula bottle with the whole day’s dose.  whenever using a bottle, use othodonic nipples so you mimic breast feeding and don’t get any nipple confusion.  Once my baby was 6 months, i would sometimes give her the salt in an ounce of juice this came out to 4 ounces of juice for the day.  Just keep trying different things that your baby responds best to.  i hope this helps and you find something that works for you both.