Firstly, flossing should be done every day, and between all your teeth, not just where and when food is stuck. Secondly, the action is important. Rather than running the floss backwards and forwards through the gaps, run it up and down against the sides of each tooth. This will dislodge any food and clean the sides of the teeth that a toothbrush can’t reach.
If using a manual toothbrush, use a soft brush with gentle force. Brush in a circular motion, focussing on the junction of the teeth and gums.
If using an electric toothbrush, don’t use force, and focus on the junction of the teeth and gums.
Purchase a bottle of hydrogen peroxide (3% or 6%) from your local pharmacy. Dilute a small amount with water (1 part 6%: 4 parts water, or 1 part 3%: 2 parts water). Dip your manual toothbrush into the diluted solution and gently brush your gumlines. Gargle or rinse with the remainder of the solution. Spit out the solution and do not rinse with water.