Applications. Generally, it is used as a buffering agent or to adjust the pH of solutions. Most commonly, ammonia solution (the A Ammonia Solution 39 concentrated form) is used to produce more dilute ammonia solutions. Therapeutically, dilute ammonia solution is used as a reflex stimulant in ‘smelling salts’, as a rubefacient, and as a counterirritant to neutralize insect bites or stings.