I quote: "Bath salts help heal cuts, burns, wounds, and insect bites. The minerals found in the salts are absorbed through the skin which is essential to the bodies' functions. Bath salts also flush out harmful toxins from the body and is a good stress reliever. It also exfoliates the skin, leaving the skin smooth and supple."
I used salts scrubs in the shower for a long time, and really noticed an improvement to my skin. I stopped using them for about 6 months, and again, noticed a change, not for the better, to my skin, so I started using salts again & my skin improved very quickly. Now I've been out of salts for about a week & using my sugar scrub in the shower, let's see what my skin does . . .
As for types of salts, I prefer to use Dead Sea, hoping that it has a higher mineral content. For my salt soap (often called Spa Bar) I used regular table salt, it's what I had on hand . . .
I read that for the soap bar you should not use Dead Sea, it will totally kill the lather.
For a lot of the recipes I've seen on the net, any type of salt is acceptable, I can't tell you how times I've seen recipes for water softner pellets. Honestly, I've been eyeballing the canning salt in the cupboard! Haven't used it, but at some point, I'm going to read the ingredient list, you just know it!
Epsom Salts are not useable in a soap bar, actually, epsoms aren't really salts. Great product, but not the same as salt. I do use them in my scrubs though, along with other salts.
Dendritic is a good salt to add in to products because of the cut of it, very fine, cut like a star, and it readily absorbs & holds fragrance. Other than that, it's just sodium chloride, like all the other salts.
As for demand, I don't know. I made my salt bar because a guy requested it, and at my next party, I will have it out to be sampled, and I'll just have to see how well it sells. It sure has a lot of competition, with OO soap, clay soaps, goats milk, geez, soaps are nice!!!!
Barefoot