Castor oil.

That's what Mussolini's fascist bully boys poured down the throats of their political enemies, force-feeding them so much laxative that the treatment amounted to torture and, sometimes, death.

I do not subscribe to the castor-oil approach to coaching writing. This is not your grandparents' ruthless English composition class.

Instead, I opt to illustrate principles of clear, concise and cogent writing through snippets and stories to loosen up beginning writers and to engage more accomplished writers to revisit fundamentals and refresh their skills.

However ... some principles do bear relentless repetition.

An appalling grammatical error pops up in the new Bob Woodward/Robert Costa book "Peril," which aims to make the case that Trump supporters are threatening democracy. And so, we return to that old bugaboo, the dangling modifier — a phrase not logically related to the word or words next to it. This, from page 10 of the book:

"[Paul] Ryan's kids back in Wisconsin were still young enough to spend time with him. Growing up, his dad had died when he was a teenager."

The reader who sent me that quote — a former church administrator, Craig Wiester of Minneapolis — said of the dad, "Must have gotten an early start building a family!"

The one growing up was Paul Ryan, not his dad.

E-mails from readers almost always come from people who love language and love discovering such deplorable and laughable examples.

How could a publisher release a book by the celebrity journalists Bob Woodward and Robert Costa containing such a basic error? How could the authors not know better? Danglers rank among the worst enemies of clarity.

If you think I am force-feeding you danglers, and they feel like a gush of castor oil, consider this: Advertisers say it takes seven exposures to an ad for a consumer to register the message.

To rid our writing of dangling modifiers may require ridicule; here's the first annual revival of the one sent in last year by Rainer Schulz, a former high school English teacher:

"Squeezed by too many other shoppers, the woman refused to buy the tomatoes."

Twin Cities writing coach Gary Gilson, who teaches journalism at Colorado College, can be reached through writebetterwithgary.com.