The salt is of the table salt kind, nothing fancy, there is no particular ratio measurement, it is usually simply blessed by a priest who knows what its main intended use is for. Occasionally it has the full Latin ceremonial.
I make a sign of the Cross with the water, that includes a particular prayer, and ask God to multiply its merits/graces/benefits for ALL souls in Purgatory.
I then spend some time in prayer for all souls, particularly those most forsaken, and those to die ‘this day’ or soon.
I wish more folks would do likewise - it is sadly amazing how much is sometimes spend on lavish flower displays, and how little is spent on prayer. Flowers do not benefit the souls in Purgatory - prayers do.