you need to check when and to whom Chofetz Chaim wrote this pamphlet.
Chofetz Chaim lived a long life, starting under the Czar, then, during WW1 and communist revolution, then in free Poland while things were changing quickly. His letters change from 1910s to 1930, starting with diukim of halocha, then to encouraging people not to overcharge refugees during WW1, and at the end, deploring people to have at least one kosher cheder per town and asking women who know how to read to teach the rest of the women basics of halochos niddah.