Well, FWIW, in DAZ|Studio you can simply CTRL+click all of the figures in the scene you want deleted, and hit the Delete Key. Conformed to something else or not, they go bye-bye.

Now in Poser, you'll have to pretty much select 'em one at a time and knock 'em out. A Python script can follow conform linkage and wipe out all conformed stuff, but I haven't the slightest idea what you would call in Poser to do that. (Stewer prolly would know offhand...)

/P