They adamantly refuse to "provide authentication services." However, if you take it in asking them what kind of leather or what color it is, they're going to tell if you if it's a fake. They won't say "That would be togo if it were real, but I can't say unless you leave it for cleaning." Even if it's togo and you know it's togo, you can always say "Is this clemence?"
So, you don't actually have to pay for a cleaning, but if you go in the store a lot, in my mind it's the least you can do to leave it for a $50-$80 cleaning after they've assured you your $5,000 or $10,000 bag is truly authentic.