1. Buy the $35 lightweight convertible stick/handheld vacuum you've been meaning to get for a while anyway because using the big vacuum on the stairs always ends with a visit to the chiropractor.
2. While paying for it, casually remark to whiny child that you're not sure if he's quite responsible enough to be able to use the Very Special New Vacuum.
3. Refuse to take the Very Special New Vacuum out of its box for 24 hours because child continued to whine all the way home. Wistfully lament the fact that you had really been looking forward to using the Very Special New Vacuum.
4. The following day, after child has spent several consecutive hours not whining, allow child to finally unpack vacuum. Express lingering reservations regarding child's ability to be trusted with the Very Special New Vacuum.
5. Allow child to persuade you into taking a chance on him. Enjoy sitting on a catfur-free sofa while explaining the finer points of vacuuming under furniture.
6. When child finishes vacuuming everything he can find, praise him lavishly for being so responsible with the Very Special New Vacuum. Reward him by allowing him to dust the bookshelves.