To rub vigorously and smooth is meant in the first instance and—those who descend from Poland, the second.
To polish one’s writing is merely the effort of smoothing it out. In some cases it may be just better word choice. There are times a sentence is written and it seems choppy and even fragmented. Skillful writers find ways to frame a sentence, allowing it to flow with ease. The same sentence as a choppy example; A good writer will get a way to make a sentence so that it will sound good and easier to read.
Thus writers look for the sharp edges. In other words, those words that tend to be like speed bumps; they slow down the story.
Now, what about the second use of Polish, as in Poland. Many Polish names end in “i.” Well-polished writing uses the personal pronoun “I” to a minimum. After all, it is understood who has written the story or article, does the reader have to be constantly reminded?
Here is an example;
“I didn’t see Robert in the grocery, but I saw him drive by.”
“Robert drove by the grocery.”
Thus two “I’s” were eliminated without a funeral and the sentence freed up. The writer must constantly remind himself, it is the story or article that is most important not me.
Like all advice it doesn’t work in every instance, but provides a kaleidoscope, of sorts, to see your writing in another light. However, try to remove the sharp edges from your writing and hold the personal pronoun “I” to a minimum.