My 4-year old twin grandsons will not keep their hands/fingers out of their mouths. After months of correcting them, I decided to spray vinegar (diluted with water) on the guilty hand part which is really upsetting to them. I know it doesn't hurt them and I have broken them of spitting and biting using this consequence of bad/unwanted behavior. However, my daughter thinks I am overusing this technique. Am I wrong to do this and is there a better way of correcting this situation? I feel that if this is so upsetting to them to induce crying and going to their room that it just might work. Through it all I show no anger or yelling. I just simply tell them that they will get the vinegar whenever they put their hand in their mouth.