generally:
If ObjecDock was installed as a standalone it would be in the add/remove unless:
it got picked up by either Stardock Central or Impulse, then you would use SDC/Impulse to uninstall it
either way, I suggest backuping any themes, backgrounds, png, icons, etc and saving your theme and backing that up, prior to uninstalling
Stardock has The Zapper which will remove all traces - I highly suggest you back up what you want to keep first