We will not advise miracle remedies, as in advertising, washing away fat in ice water. Instead, we will share the grandmother's method of how to do it, which will not be harmful even to children after washing.
For greasy dishes, when there is no hot water in the tap, you should use mustard powder. Dilute it in the water in which you will wash, or pour it on a sponge and thoroughly rub the plates.
Not only fat, but also old plaque can be washed off quite easily. If you have a large number of dishes, we still advise you to find a way to heat the water in order to pour it into a large bowl and pour the powder. For 1 liter of water, 2 tbsp. mustard