Just about anything you can put in your body that is enjoyable is harmful in the long run. I know folks that dip, drink, smoke cigarrettes and weed, and pee from the stand, . . .seriously. Every now and then they'll kill a doe or something. While I don't hunt with them, and they have their own private little club I guess their still having a good time.
Myself, I'm scent concious and go to great lengths to keep scents down. My hunting clothes are washed in non scented detergent and then kept in a cedar tree outside. I bathe in non scented soap just before I go outside to get dressed. I place garbage bags on the truck seat to sit on while I drive to the woods. I never oil my rifle during deer season except to swab the bore. I fast before a hunt not eating or especially taking in liquids. I keep deer pellets in a freezer bag and wipe the bottom of my boots with them before walking to the stand. Plus I spray a scent killer all over myself before going to stand and after I get there. . . . . .I then climb my stand, get settled, and take a big ole dip . . . .Can the deer smell it? I'm sure they can. Even though I keep a small bottle to spit in. . . . .it's a trade off to enjoy my little vice. I've been winded before and have been busted moving around to spit in my bottle. . .more than once.
I've killed several nice deer, but then again I've been hunting and dipping for 35 yrs. I've never killed a record book deer and I believe to do so requires a lot of luck and giving oneself every advantage one can . . . . .dipping is not an advantage unless you just can't be still without it, and I agree that it takes away from scent control and keeping movement down.
I own a few acres and I feed the deer here at the house all yr round. This yr I'm not hunting my land yet but have been pretty much daily walking over it disregarding any scent considerations. It seems that deer get acclimated to scents after awhile if their not being hunted. My biggest deer have been killed right here on my place . . .no telling what the dip is doing to me in the swamp where I hunt.