You can certainly treat a hire as a piece of meat and dehumanize them, but I disagree that the act of engaging them is inherently dehumanizing.
It's a job. I often didn't like my work. But, it paid well and I did it. Why is that any different than this? Perhaps you can argue, and I don't think I'd disagree, that most work is dehumanizing. If you're working, it's almost always because you have to. Different forms of economic vulnerability, but still most people do it because they have to. I do not subscribe to the notion that sex work is somehow inherently worse than other jobs.
If you don't want to dehumanize the guys, don't be an asshole. It is amazing how many social interactions go so much better when you aren't an asshole.