This isn't from the periodic-cleanse side but is more from the maintainance side: stay away from all processed foods, GMO's, artificial colors & preservatives, and synthetic pesticides.
Water-wise: to remove fluoride, chlorine, chloramines, and other chemicals, get a reverse-osmosis system or use the reverse-osmosis systems that many grocery stores have and make sure to refill with BPA-free containers.viewtopic.php?f=47&t=13609&p=192900&hilit=#p177599
An apparently underrated and overlooked thread^.
Also it is best to add a few grains or so of Himalayan salt, or some drops of liquid trace-minerals, to every glass of reverse-osmosis treated water, in order to re-mineralize it.
Or take a good daily whole-food vitamin, such as the ones made by Garden of Life; because heavily-processed non-whole-food vitamins have actually been shown to be not only a waste of money, but are actually bad for you to boot. Non-whole-food heavily-processed "vitamins" also lack bio-flavonoids and enzymes.
Whole Vitamin C (such as from organically-grown citrus fruits, Ayurvedic Amla, Camu-Camu fruit, or lypo-spheric Vitamin C) is great for detoxing too.
The "ascorbic acid" found in heavily-processed non-whole-food vitamins is not really Vitamin C, as 'ascorbic acid' is only part
of what makes up Vitamin C; and, 'ascorbic acid' lacks bioflavonoids too.