Probably exfoliates the hands. Honest. But you are right about the distressing visual effect of ageing hand-skin in a Dyson.
I think you may be thinking about the vacuum cleaners that dear Sir James invented, my dear, that suck, and do so very effectively I find. Do not, repeat not, use these to dry your hands with. That would be so wrong in all kinds of ways.
And do not, double do not, apply any part of one of the esteemed Sir James's admirable vacuum cleaners to any part of the anatomy, darlings. Or anyone else's anatomy. There is no truth in any of the intriguing rumours you may have heard.