The best cleansing you could do is drinking lots and lots of (clean) water.
Could you do chelating along with other cleanses? It really depends on your body. I would definitely go easy at first and test your body's ability to get rid of the toxins. Overloading your body with released toxins is a good thing to avoid.
I think chelating and bowel cleansing would be OK since the things cleansed from the bowel will be going directly out of your body anyway. It might even be helpful to do it with chelating since it would presumably help remove metals from the intestines as well. Of course, you should be careful about doing the bowel cleansing for too long since your body may become addicted to the supplements used for cleansing.
For chelating I've used Cilantro/chlorella and the Cutler Protocol. Both have been helpful. I usually recommend the Cutler Protocol for beginners because everything is laid out fairly clearly.
Cilantro/chlorella is very effective, but it's really important to use small amounts regularly. Don't fall into the trap of eating a whole bunch of it every so often like some people have done (often with bad results).
I would definitely find out all you can about a particular method of chelating before you begin using it.