haha, milking the forums for all its worth, eh?.... good idea. if you want to know the layman's advice (which is me), you could try another method:
-make a normal shortcut (i.e. dragging the address to the desktop)
-simply change the icon of that like you normally would
-drag that sucker onto the dock and there u go.
hmm, not sure if you need to keep the o.g. shortcut or not, but it does beat the hell out of hacking into the OS, besides, shortcuts dont take up that much space anyway. herd them all into a folder and ur set.