The receipt of such a bomb is very simple.
You will need:
Blend the salt and citric acid together, add soda, grapes seed oil. Mix well the ingredients until smooth. Spray some water with a pulveriser to make the formula sticky. Add the essence oil.
Put the mixture in a mould, quite tightly but not taking great pains, otherwise you will not be able to put it out of the mould if you go too far in pressing.
Fill one half with the mixture in a hill way, and put the halves together pressing them to each other. In several minutes you can take them out and dry!