Scraping vs not scraping

I’m brand new and just cleaned the windows on my house. It required a lot of scraping - windows had not been cleaned in 5 years. I’m concerned because I am hearing a lot from contractor friends about scratching low e windows. how do you clean these types of windows if you can’t scrape them? How can you tell before starting the job if the window is safe to scrape or not? Are there safer alternatives to scraping that still does the job and won’t harm the window?

There is no fool proof way to determine the presence or absence of Fabricating Debris. I make sure the customer signs a waiver before we start work. You can’t scratch a properly installed low-e coating because it should be applied in between the sealed IG unit.
As for “safer alternatives” they don’t exist! Any alternative that removes stubborn dirt or debris carries it’s own set of risks.