Show the object. Hide in easy place. Find it with a bit of help if required.
Hide it again, a bit more difficult this time. Find it.
Carry on as usual.
Don't think it will take many goes to remember.
This is more about following a trail than scenting the object.
I can show two balls and then hide them.
Now he finds one, drops it and looks for the other.
Took a bit of practice but not a lot.
Well perhaps not quite. If the first find is a favourite then he retains it and just indicates the second.
I hide people also. Really easy to find.
Little treat things are hard to locate exactly. Don't give a clear scent to home in to.
What will take a lot of time is working to an instruction like:
"fetch blue ball" "fetch Santa" "fetch Monkey".
Can be done but they find this level a bit too far.