There is meticulous preparation in the build-up for ultra events.
When one or more blood vessels in the kidneys become narrowed (renal artery stenosis) because of debris and plaque build-up, or blocked because of a blood clot (renal vein thrombosis), the kidneys are unable to function properly.
Finally, there is a heart health product line that has added CoEnzyme Q10, which is known for decreasing arterial plaque, and added amino acids, which are known for preventing fatty acid build-up in the heart.
A detoxification fast may or may not help your body rid itself of toxins, but the only way to effectively detoxify over the long term is to avoid those products that cause toxic build-up in the first place.
For stubborn build-up, you may need to apply vinegar, a thick paste made from baking soda and water, or a commercial rust removal product to loosen the rust enough to allow you to scrub or scrape it away.