An AppleScript solution.

Code:
set thePath to ((path to library folder from user domain) as Unicode text) & "Caches:com.apple.Safari:Webpage Previews"
tell application "Finder"
	if (exists folder thePath) then
		delete folder thePath --move "Webpage Previews" to Trash
	else
		display dialog "Folder doesn't exist."
	end if
end tell



dkmarsh—member, FineTunedMac Co-op Board of Directors