No. You putting iodine solution is not for cleaning the onion but actually testing for starch. Onion is a plant that makes food. Thus, onion contains starch. If you put iodine solution onto starch-present organism. the brown solution will change to darkblue solution or blueblack solutiom due to the presence of starch. If there is no starch present, the solution will remain brown. Hence, the iodine solution is npt for cleaning but for testing for the presence of starch.
