This hot drink method is often used with the cell salt Magnesium phosphate (EU No. 7 or US No. 8).
In Germany the hot drink method ist therefore called the "Hot Seven".
But you can use the hot drink method with all cell salts. You can even mix several cell salts to prepare a hot drink.
How to prepare a hot drink?
Put up to 10 tablets in a cup.
Pour hot water in the cup.
Wait until the tablets resolve.
Drink the hot drink in small sips.