A salt water rinse can temporarily reduce swollen gums. More importantly you need to find out what is causing the swelling. Swollen gums are usually a sign of gingivitis. You'll need to have a thorough cleaning with a dental professional to adequately address this problem.
Swollen gums can indicate a serious health problem. It may be a symptom of a systemic infection among other things. Finding a method of mitigating the symptom is not what is called for. You really should see a dentist or other health professional. Dental schools in universities often operate low cost clinics. Don't wait.
Salt water rinse can help swollen gums. Mix 1 tsp. salt to 8 ounces of warm water, stir and swish around in your mouth. You can also swish with an antiseptic mouthwash. It is important to see a dentist if you have this condition as it could be something serious.