Booklet as insulation for home?

At the next village, the team tossed out the trial booklets, but when the villagers began collecting them, the team shifted to handing the booklets out—as insulation for the villagers’ homes.

An excerpt from book "Atlantis: Gene". How can booklets be as insulation?

Solution 1:

It is a way to say that the written contents and ideas of the booklet are worthless. The only value of the booklet for the villagers at least is the physical paper.

Insulation means stuffing it in the walls or between sheets to make a thicker blanket.

It is meant as as an insult about the booklet. A common insult about a newspaper one thinks is junk would be to say that its only use is to line a bird cage.

A similar example is in times of hyperinflation when a banknote's cash value is approximately the value of the paper itself or less. At least such a statement is made figuratively:

Venezuelan Bolivar Now Worth More as Toilet Paper Than as Money