There are lots of minerals in water, some natural and some added. Often fluoride is added to promote dental health, but it occurs naturally in many areas. Sodium and chloride is almost always present to a small or large extent, depending on the water source. None of those cause scale nor interfere with soap.
Let us review the problems with hard water, then the cases, then the solutions. Then we will consider Hannity. This is Kos, so some political stuff should be expected.
The major problem with hard water, from an economic point of view, that it tends to drop its minerals in industrial water piping, lowering the transport capacity for the pipes. This is much more of an effect when the pipes are heated, so the term boiler scale is appropriate. It can happen in cold water pipes, but almost always is much less important. In domestic situations, it is just about confined to water heaters.
In other domestic situations, hard water causes shower heads to perform poorly (Hence the CLR adverts, and CLR does indeed work), causes water spotting of dishes that are not treated with a drying agent (for mechanical dishwashers) or hand dried, and causes the dreaded bathtub ring, a combination of metals other than sodium or potassium with soap (detergents are pretty much immune, and that is why we use them so much).
Except for your water heater, hard water is more a nuisance than a problem. If yu use a product like Jet Dry in your dishwasher, or hand dry handwashed dishes, you will not see it much. If you use a shower cleaner now and then, it will not deposit on your shower stall, on make a bathtub ring.
The chemistry behind hard water is simple. Much natural groundwater (surface water to a lesser extent) contains calcium and magnesium ions along with chloride, sulfate, carbonate, bicarbonate, and, in agricultural areas, nitrate. All of these are soluble to some extent in water, calcium sulfate being sort of the exception. There is often some silica involved as well. When water containing these ions is drawn into boilers, the calcium (water hardness is almost always expressed in terms of calcium, even if other elements are present) tends to precipitate out as the calcite form of calcium carbonate, CaCO3. This is a fairly aggressive form of CaCO3 as far a scale in concerned.
There is another form of CaCO3 that is less prone to clump together, called aragonite. It has the exact same chemical formula, but crystallizes in a different form that is not so prone to interlink, and just pass on rather than coat the water supply tube in which it moves.
It has been found that with some electromagnetic waves impinging on the source water that aragonite is favored. It takes quite a bit of energy, but for commercial boilers, and in particular recirculating loops, this is cost effective, reducing scale quite a bit. It takes a magnetic field of around half a Tesla to do that effectively, and the more circulation the better, because there seems to be a memory effect, so a one pass treatment is not as effective as continuous treatment is.
Now to the hot air. There is a firm that calls itself Easywater that claims to use this technology for home use. The name is a play on word for hard water, and their claims are plays of words for effectiveness.
I went to their site, and found a unit that costs around $2200.00. The claim is that it will "soften" your water. I will not, as I will demonstrate.
Hard water is caused by mineral content, and boiler scale can be modified by the aragonite to calcite ratio. But that has nothing to do with your dishes drying in the dishwasher, or your dishes draining on the rack. Those minerals are still there, and drying spots care not if the calcium carbonate is aragonite or calcite. They are still spots.
I also did some calculations, and the magnetic field, even with very liberal limits, that Easywater uses could not possibly do what they claim. The literature for this technology indicates that at least one or more orders of magnitude of exposure is required, and that would take lots more electricity. You are better off washing things and using CLR now and then.
I did the math, and, if folks are interested, can produce numbers in the center of the pipe. The magnetic field is not impressive. Nor is their claims that they use a "different" kind of field. It is nonsense
So, since the hot air part is finished, the Hannity part. Easywater is his new advert friend. He had to get a new one when Stanford (the gold broker and accused Ponzi scheme character) was seized by the authorities. Anyone that takes an advert on Hannity does it at her or his own risk.
Any thoughts, comments, and corrections are more than welcome.