The 34-year-old model - who was born in Sydney, Australia - has admitted when she is at home she will always take a dip in the sea and when she gets out of the water she will "scrub" her skin with the natural mineral, which is a ritual she has carried out ever since a young age.
Speaking to Vogue.com about her beauty hacks, the golden-haired beauty said: "Australians really like that clean, healthy, fresh skin, and slightly underdone tousled hair.
"[We] embrace natural beauty. And I feel like that's reflective of the active lifestyle and being [outdoors].
"When I am home in Australia, I go for a swim in the ocean, and after getting out of that salty water, I'll go on the shoreline and scrub my skin with the sand."
And when the fashion icon - who has six-year-old son Flynn with her former partner Orlando Bloom - is not near the salty ocean she will run a bath filled with baking soda and sea salt in a bid to cleanse her body of any toxins, which she claims helps cure any jet lag too.
Speaking about her DIY skincare program, she said: "Another thing I do is take a bath. I make it super hot and I put a pound of baking soda and a pound of sea salt and that draws [the toxins] out of your body."
Miranda - who is set to launch her own skincare range Kora Organics this week - will "never" leave her home without her Noni Glow Face Oil, which helps to keep her flawless complexion hydrated.
She said: "I never travel without it--it's the best thing to keep my skin hydrated.
"It's a super easy and quick way to nourish my skin."