I have this feeling that my teeth are not clean after wisdom teeth extraction. what can i do?

Rinse and brush: You should still be able to rinse vigorously , not disturbing the healing blood clots if present, with warm salt water, brush back to the second molars and floss as well. The "feeling" is a warning. You need better oral hygiene habits. Not a lecture.....Just the truth.

See your dentist: If it has been a few months or more since your last professional dental cleaning, i would arrange to have that done. Your hygienist can clean all areas very well, most especially the surfaces that contacted the wisdom teeth.