How can I add salt and get it to permeate throughout chocolate? Based on a previous question I understand it is not possible to make chocolate from home since specialist and expensive equipment is reqiured.  As such I bought premade dark chocolate from the shop, melted it(brang water pot to simmer, added anotther pot wih chocolate in to top of first pot). I then added salt in as I wanted to increase the salt content of the chocolate ensuring the salt is distributed well.

When eating the chocolate I noticed that the salt did not distribute throughout the chocolate and the grains didnt even dissolve properly. large salt grains were present in the chocolate.

I then melted some coconut butter in the same way, added salt and noticed the salt grains didnt dissolve either so clearly need to do more to get the salt to dissolve and distribute.  I added water to the coconut butter and it the salt did dissolve however it seemed to still be seperate from the coconut fat in the same way oil seperates from water.  I then added coco powder.  When I ate it although the salt grains did dissolve it still seems not to have distributed/penetrated the chocolate well.

Chocolate bars with a high salt content e.g. twirl, flake have the result i'm looking for i.e salt is distributed well throughout.  Anyone know how i can get premade chocolate, add salt and get it to distribute like the aforementioned bars, or cook from scratch getting the salt to distribute properly?  I cant just use the aforementioned premade bars because they have many other ingredients which I'm trying to avoid. 

-- UPDATE --
I have just noticed that the chocolate bars I have been comparing to e.g. twirl, flake do not have salt added as an ingredient.  However they still have 0.25g of salt per 100g of chocolate.  I guess it means its naturally occuring as a result of one of the ingredients or managing to merge that ingredient with the other ingredient hence getting the seemingly well distriuted salt.  Does anyone know which ingredient gives it the salt(I'd guess milk).  If I wanted to then emulate the recipe would I simply melt chocolate as previously and then add milk, is there some possible way to make the salt distribution like aformentioned store bought chocolates now that I know it definately wasnt as a result of adding/cooking salt?
You can't. Salt is water-soluble, and chocolate is made out of starch suspended in fat, without water. You cannot dissolve the salt in the fat. 

Adding small amounts of a liquid in which the salt is dissolved will also not help, as it will curdle the chocolate. At least it will certainly happen with water. Alcohol can have some chance of working, as it dissolves both polar and nonpolar compounds, but you will need pure (96% medical) ethanol, not an alcoholic drink. I think this is quite impractical even if it works, but you may want to experiment with it. A commenter who has tried it notes that not even alcohol will work.

The closest you could do at home is to make a ganache with either cream (standard) or water, and dissolve the salt in the water phase before making it. The least amount you can have is 20% water (if using cream or another liquid, you have to adjust for its solid content so you end up with 20% water in total). This will give you a creamy ganache, and quite concentrated, but not a chocolate bar. 

The only other thing I can think of is to go the way you already did - retemper chocolate and adding salt while melted - but you will not have it dissolve. What you can change is to grind it into a fine powder first, so you don't feel the grains as much. But it will still be grains suspended in the chocolate, not salt dissolved throughout the chocolate.