Depending on what kind of food you have eaten most of your life, a simple fast might be all you need to cleanse & refresh your body. Liver flushes and things like that are for people (like me) who have eaten SAD (Standard American Diet) for most of their lives. (This would consist of prepackaged foods, fried foods, snack foods, etc). A lot of cleansing can be done simply by removing these foods from the diet & eating more fruits & veggies (prefferably raw). A good website to visit would be http://www.goneraw.com
just to get an idea of the different ways these foods can be prepared so that they're not too boring.
As for oil pulling, KUDOS! I've just started myself, and after only a few days, can see the benefits!