Ahahaha! I was just going to post, "Maybe a little rat poison in his Jack?"
Now I'm honestly curious to what her "cure" was and why it took her twenty years to come up with it.
This is reminding me of the time Jim Carrey was on SNL and did a bit about "Ride The Snake", which was a mix of uppers.

Why does she have nothing to sell but won't publish her cure in the paper?
Even by early-1900's standards, she is too pretty for me to say, "If you were married to her for 20 years, wouldn't you drink, too?"
At that time, divorce was expensive, very hard to get, and publicly humiliating (especially for the woman), which was a big deal. If she had children, she'd lose them, even to a drunkard. Things have come a long way.
You had to be able to prove that he had committed certain specific "sins" to qualify for a divorce. Infidelity was one, and so was physical abuse, but you had to be able to prove it. Alcoholism was not grounds. I think "failure to support" would work, but only if he never gave you a penny. (By the way, marital rape wasn't grounds because it legally didn't exist until the 70's. Before that, marriage gave him total access to your body any time he wanted. OTOH, if you refused to perform your marital duties, that was grounds for him to divorce you.)

You also had to make sure your behavior was beyond reproach. Divorce was only granted to an "innocent" party. If you charged infidelity on his part, and he could claim you were also untrue, there was no innocent party and you couldn't get divorced.
If she were serious, wouldn't she have put the free remedy in the copy of the ad?
The ads were a front for a company selling a fake cure for drunkenness called Alcola, various pills which contained strychnine, among other things. The letter from Mrs Anderson would advise the writer to contact the Physicians Cooperative Association in Chicago, who sold the pills. A detailed writeup can be found via Google Books in "More Secret Remedies: What They Cost & What They Contain" page 137.
I love how the ad brags that "noble" Margaret is "HATED by the Whiskey Trust".

(To be fair, alcoholism did destroy a lot of lives then- in urban communities, it was the bane of the working class, men drinking their meager earnings away as kids went hungry. Early feminism was very tied anti-alcohol feeling that eventually became Prohibition. Because they and the kids were the ones who bore the brunt of mens' carousing, which actually was more serious than we appreciate today. What we consider raging alcoholism today was considered somewhat normal then. And except for German biergartens, it was indeed whiskey they were drinking. There wasn't many lighter options than that, they went for the hard stuff. )
Ahhh, I miss the refreshing taste of That's All brand whiskey. Things were so much better before that Anderson witch had to go after Big Whiskey.
anyone else notice the backward e in "sell" under "rememdy is" in boldface? it's bothering me...