"Avoid GMO's" is terrible diet advice, especially for claims that it will clean out your body. It's true that some GMO's are specifically designed to handle much higher levels of pesticides, and perhaps you'd decide to avoid those. I don't blame you. But, GMO as a concept is something that should be celebrated. There are also many conventional foods that are sprayed with various kinds of pesticides, and even organic farmers can use certain pesticides as long as they are not synthetic.

So, if you really want to give dietary advice on what type of food to eat, suggest starting a garden and getting into eating local vegetation in wooded/forested areas (probably illegal to take food from the woods). I personally get massive quantities of walnuts, apples, various berries, cherries, and a few morel mushrooms from the wooded areas around me. It really saves on the grocery bill from spring to fall. Not to mention soil depletion. The stuff you haul from the woods is obviously nutritionally superior.

There are also many other ways you could actually "clean out your body," or become more healthy in general, without resorting to reading health blogs. According to the scientific literature, you should avoid sugar and other carbs, eat more good fat, protein, vegetables and fruits. Saturated fat is no longer considered detrimental to cardiovascular health. There is nothing wrong with a nice steak or some whole milk yogurt. The optimum type of meat/dairy is grassfed or pasture-raised because of higher omega-3s (and other differences in fat composition). For additional omega-3's, either consume some type of fish-oil supplement or eat low-mercury fish, such as sardines (biomagnification).

What else...

Avoid BPA. There's plenty of evidence that it's bad for you.

A study from Israel a few months ago found that aspartame causes diabetes.

Magnesium supplementation is a really good idea for most people. http://www.sciencedirect.com/science/article/pii/S0306987706001034

The very low RDA for vitamin D was a result of a mathematical error, so if you went by those recommendations, here's an update: http://www.sciencedaily.com/releases/2015/03/150317122458.htm

Hopefully you see my point. Nutrition and toxicology are extremely large areas of study and very complex, always improving. I just thought I'd give an example of generic dietary advice, rather than a poorly-thought out slogan, such as "avoid GMO's."