I take it as powder, downed with water, but capsules are an option, so are tea.
I havent done regular salt flushes; maybe someone else will answer this one.
I followed the watercure for a couple of months (2 liters of water with 1/2 a teaspoon of salt per liter daily)
Now I drink saltwater morning and evening (I have a craving for it), + sometimes extra if I feel I need it.