@Johnny - Drinking salt water would be a very silly thing to do. Not to be recommended.
As for this idea of a kind of cleanse, or "detox" - what, precisely, do you imagine you are detoxing? The body is a wonderfully adapted mechanism of intermeshing organs, all homeostatically controlled, and this idea of detoxing is largely a fad designed to part people from their money.
If you wish to reduce some of the stimulants that your body is exposed to - coffee, alcohol, nicotine etc, and if you wish to restrict the calories your body consumes, these are worthy aims - but the idea of a detox to remove accumulated toxins is, simply, bunkum.