Hi & Welcome. I appreciate your idea of having a warm water gargle mixed with Amoxicillin. Gargle done this way may not be effective for the treatment of Stroptococci positive infection of the tonsils. Basically the medicine Amoxicillin is intended to be taken orally to get absorbed from your intestine to reach the blood circulation so that the offending organisms (Streptococci) which are responsible for the infection of the tonsils get killed. The efficacy and safety of Amoxicillin mixed with saline water gargle is not proved and hence not approved by FDA. Dear, since you have been taking it as a part of RCT done recently, why do not you continue to take the medications as prescribed by your treating doctor who knows much more about the drugs and how to use them to get their maximum efficacy. Hope to have answered your query. A feed back is appreciated.