Please do not use copper unless you have a seperate tank that you will NEVER use in the future for keeping Inverts.
Cleaner Shrimps are good as a precaution but not cure of White Spot. In fact i dont think they can physically remove it.
If your fishes are already seriously infested with white spot, i would suggest you remove them and do a FW dip.
If your fish are very mildly infected, then as Spider said, just use Garlic and maintain high quality of water.
If you have no inverts in your tank, you can Very gradually lower your S.G to around 1.016. But then again, its not a cure.