Tim: I take it that this is your "You've given me a nice idea, see below" reference?
Yes, the Black Baron has gone, or was it Count Yerself Lucky? Strange how memories of his name begin to dissipate into the ether. Must be down to Aura activity.
I think Dumbledore may have been more lenient with the deatheaters than Potter's Punishment Patrol. The first task would have been to track down all of the Earthly Earl's supporters as they will have gone to ground and scattered. Dumbledore's magical prowess would have enabled him to combat the protective charms on the dark marks and put a trace on them, enabling all wearers to be tracked down eventually.
In return for permanent 'tattoo' removal, each wearer would have to be obliged to do something/promise something - but what? Repair damage done during their reign of terror? Cue bridges being rebuilt overnight. The kindly wizard would be more inclined to take the 'word' of the Knight of the Night's supporters when they swear allegiance to the forces of good.
However, Potter and Weasley Aurors Inc are more likely to want high-profile humiliation, especially after the loss Ron experienced. Expect to see followers of the Darkside Duke scrubbing lichen off the Mount Rushmore carvings with a toothbrush, doing a shift as replacement lightning conductors on the Eiffel Tower, scouring pigeon poop off Sydney Opera House - with their tongues, following behind abundent herds of wildebeest in South Africa with besoms and dustpans and packaging the by-product as fertiliser, walking the length of the M1 Motorway and trying on every traffic cone to see which ones would serve as a replacement Sorting Hat, painting the Golden Gate Bridge with a 3-haired watercolour brush, etc etc.