How long do I have to leave my sealed envelope in the freezer until it unseals itself?

I read in a recent Popular Science magazine that you can unseal an envelope in the freezer, but I don't recall how long it would take for it to pop back open. Anyone know the time it would take?How long do I have to leave my sealed envelope in the freezer until it unseals itself?
Never heard of that one . Be glad to know myself .How long do I have to leave my sealed envelope in the freezer until it unseals itself?
Much quicker and easier to steam it open. It really does work.

Do it gently and keep testing it with a butter knife until it gives.

Should take about a minute or so.

natural cleansing