From my experience I have to say it's pure evil. I've written utilities like this before on request for the very reason you noted Stig, but when I did it I saved the original properties so they could be restored at a later date if needed; kind of a round trip kinda thing.
But to repeat, from my point of view it's generally PURE EVIL to supply code to do this. There's a lot of CADD Operators who don't like following CADD Standards, find using layers "a pain". These folks will use a utility like this (without approval) undetected for months, creating buckets of unneccesary work for the CADD Janitors, who have to fix the drawings before they're turned over to the client.
Points of view vary, this is mine.
