Such a saline is possible to make yourself.
I used saline from a bottle for contact lenses to bath,
1 teaspoon (3 grammes) of kitchen salt in a litre of water. Boil up and let boil a good while to get it as sterile you can, as it shall be used on eyes here.
Hospitals do also use this trick. Useful also for cleansing of minor wounds, scratches and so. Pour profusely.
Dont spare too long, better to make a new batch.
Its no remedicum for all problems, but clearly better than just using common water, which is what folks usually uses.