A phrase that might sound dirty but isn't

One copy editor duty is to keep vulgar words and phrases out of the newspaper — or at least, to alert a decision-making editor about an off-color reference, even in a direct quote.
Last week, I edited a story that included a quote with the phrase "balls to the wall." I thought that reference that might not be proper for the newspaper. I looked it up.
It turns out that "balls to the wall," which means an all-out, full-speed-ahead effort, does not have anything to do with male anatomy. Instead, it comes from pilots, according to several sources.
From WordOrigins.org.

"The phrase balls to the wall, meaning an all-out effort, comes from the world of aviation. On an airplane, the handles controlling the throttle and the fuel mixture are often topped with ball-shaped grips, referred to by pilots as (what else?) balls. Pushing the balls forward, close to the front wall of the cockpit increases the amount of fuel going to the engines and results in the highest possible speed."

Here is a short piece about the phrase from Slate. The IdiomSite has two possible origins for the phrase. Even the Urban Dictionary says the phrase isn’t a vulgar reference.

I was prepared for an editor’s or a reader’s question about the phrase. I haven’t heard from anyone yet. My theory is that the readership for that story, which was about a rock band, wouldn’t find anything offensive in the phrase.

This article was originally posted by the Raleigh News & Observer, a subsidiary of The McClatchy Co.; is posted here to provide continuity; and is copyright © 2011 The News & Observer Publishing Company, which reserves the right to remove this post.