Sprinkling salt to remove snow is such a common idea, but I had never thought to use it in the freezer. It really reduced the ice deposition inside the freezer and on the chilling coils underneath. I am saving some electricity for this idea. Whatever small amount that may be.

Salt is much more corrosive than normal water. Though the corrosive action gets reduced in lower temperature, still, unless the metal of the freezer is suitable for use with salt water, any contact with salt should be avoided. However, the freezer being an appliance for food, in normal circumstances the metal should not be corrosive to salt water. However, the same is not true for the chiller pipe metals. Hence if someone is interested to use this idea on regular basis then it's best to consult the manufacturer of the refrigerator to know if there is any adverse effect of salt.

About the lasting of the effect, it should be different between the users, cities & seasons also. Normally we put the defrost "on" every Saturday night. After getting the idea from your site I used to rub salt on the freezer base and chiller pipes on Sunday morning. It seemed that the amount of frost deposition was reduced by at least 20%-25%. But now I want to stop this implementation as I am not sure of the effect of salt especially on the chiller tubes. However, I am sure that there is no chance of any appreciable corrosion in this very short period of my implementation of the idea.

I think one effective use of this idea can be in the situation where an ice-tray has got stuck in the frost of the freezer. Sprinkling some salt and water on the freezer base will help to free the ice-tray quickly. Then more water can be poured to wash away the ice. I think such rare use of this idea will not do much harm to the refrigerator.