You may want to look into changing your diet. Just for starters, dairy and wheat are mucous producing foods which, among other things, help build up the mucloid plaque on the bowel walls. Also, dairy and wheat are not very nutrient dense. A diet with a large variety of vegetables, nuts, and fruits is much healthier.
You can do a Liver Flush as long as your bowels are regularly moving (at least 2 or better 3 movements a day.) However, an enema / colema or colonic after a Liver Flush is very often suggested to help get any released toxins OUT asap. If you don't like the idea of doing an enema, look into doing a saltwater flush the morning after flushing (or the next morning at the latest.)
The length of a Bowel Cleanse can vary from weeks to months - every body is different. Best advice is to learn to listen to your body and let it tell you when you're done bowel cleansing.