You need not to place cotton on tooth. Let it heal by its own. Rinse thoroughly your oral cavity with water whenever you eat something. Warm saline water rinses two to three times a day, use mouthwash.

Hello... No you should not place cotton on the extraction site now... If you want to prevent infection you just have to rinse well after your meals, brush properly and do warm saline rinses. Chlorhexidine mouth wash usage- take 15 ml of the mouth wash (do not dilute with anything) swish it in your mouth for 30 sec and spit out. Do this in the morning after breakfast and in the night before sleeping. Avoid using anything for 30 mins after using mouthwash.

Don't dilute chlorhexidine mouthwash use it directly and dont put cotton on teeth as its not required and moreover cotton can stick to the extraction socket and create a source of infection at extraction socket