How to kill bedbugs, 1777
“Spread Gun-powder, beaten small, about the crevices of your bedstead; fire it with a match, and keep the smoak in; do this for an hour or more; and keep the room close several hours.”
The Complete Vermin-Killer: A Valuable and Useful Companion for Families, in Town and Country, 4th ed. (London, 1777), 4.
The link is here. That is from a new-to-me blog, askthepast.blogspot.com. Here is “How to Make Pink Pancakes, 1786,” and you will find numerous other excellent items. Try “How to Sober Up, 1628” or “How to Grow a Beard, 1539.”
For the pointer I thank the excellent Hollis Robbins.