Not strictly speaking true if you use an applicator and pay attention.
You're right, though, that it's easy to accidentally get the stuff on you just as it's easy to get polish on you if polishing.
"Unless you're wearing gloves you're getting residual
reno from the cloth leeching into your skin regardless.
Do you suggest using gloves to apply it then?"
I started wearing gloves years ago when I polish. Not, originally, because of safety concerns but because it speeds up cleanup substantially. I buy a bag of cheap disposable gloves in the cleaning materials section of the supermarket for a couple of bucks. They're called "disposable" but the pair I'm currently using I've probably used about dozen times. I squirt some talcum powder into them the first time I use them and as a result it takes no longer than about 20 seconds to put them on and 20 more to remove them. That's *much* less time than it would take to wash and scrub off polish if I accidentally got it on my hands. It just makes life so much easier. (I think I probably first started doing this back when I was still riding horses. Maintaining a dress riding boot is a much bigger deal than maintaining a pair of shoes.)
It was only later that I learned that it makes it much safer too.
Think about it. Any "leather conditioner" that works has to penetrate tanned and finished dead leather. Your live skin is more permeable than that by an order of magnitude, I would imagine.
Hope that helps.