"Getting difficult to apply deodorant"? Seems like an oxymoron. I've been using deodorant for 30 years, and it has NEVER seemed "difficult."
And anyone who is worrying about whether deodorant is or is not "difficult to apply" has way too much free time on their hands.
For the record, I shaved my pits once (nearly 20 years ago) as an experiment to see how they would look and feel, and have never done it again. And I don't like seeing gay or straight guys with shaved pits. It makes them look 12, or whatever age they were before they had hair there.