You could try lukewarm saline rinses 36 hours after the extraction. They will help remove the food particles. Do not be scared of infection. After most extractions antibiotics are given to prevent infection.
Sometimes what you think might be particles of food is actually the clot which shows your extraction wound is healing. Do not be scared but follow good oral hygiene procedures.
Next Steps
Follow all the instructions given by your treating dentist.
Health Tips
Do not do vigorous rinsing or brushing on that area for 48 hours after extraction. Use a baby toothbrush after to clean since it is gentler.