Keeping freezers clear of ice

[rescuer]

There are regular ads for a piece of material which it ia claimed will keep a chest freezer free from ice and the need to empty to defrost

[Postdog]

You're right, so there are....

[rescuer]

Very clever Postdog!
Yes I didn't ask if anyone had found them to be effective.
It would also be interesting to learn, if they are effective, from what substance are they made.

[DeathStalker]

Probably has a salt base to it (NaCl).

[beso]

We use one and yes it does work. I have been really surprised by its effectivness. It does not eliminate the frost but the reduction is quite dramatic.

I have no idea how it works.