We will never own a cage dryer
It would let us take thirty dogs a day instead of twelve. That is the entire argument for one, and it is not enough.
Every few months somebody who knows the trade stands in our drying room, counts the stand dryers, does the arithmetic, and asks the same question. You could take thirty a day. Why don’t you?
Because a cage dryer is a box with a fan bolted to it, and the dog inside it is alone.
What the box actually does
Put a wet dog in a warm box and the surface dries first. The coat looks finished — dry to the hand, fluffy at the tip — and the undercoat next to the skin is still damp. That damp layer is where the mats form, where the hot spots start, and where the smell comes back on day three. A dog dried in a box and a dog dried by hand can look identical leaving the building and be entirely different animals a fortnight later.
That is the technical objection, and on its own it would be enough.
The other objection
The other one is that nobody is watching. A dog in a cage dryer is unsupervised by design — that is the labour saving, that is the whole point. Which means the panting, the scrabbling, the stillness that is not calm, the flat-coated retriever who has decided she cannot get out: all of that happens with nobody in the room.
Dogs have died in these things. Not often, not here, not at any place I would send my own dog. But they have, and the failure mode is always the same: the person who would have noticed was busy doing the work the machine was bought to free them up for.
The arithmetic we chose instead
Twelve dogs a day, four hours each at the outside, three people, one table each. It is a worse business on paper than the same building running a bank of boxes, and we have made peace with that by being more expensive and booked further out.
If you want to know one thing about a grooming salon before you leave your dog there, ask what they dry with. Not because everyone with a cage dryer is careless — plenty use them carefully, on a timer, in the room, with the door open. But the answer tells you what the business optimises for, and you will learn more from it than from the photographs on the wall.