Ooooh, 2o2o irritates me for some reason.... I like running contacts because they don't break up the flow of the course. 'Course Luna's small enough that she almost
never jumps over the contacts, so it's never been a problem for us. I dred the day I get a bigger dog and have to actually teach contacts.
Seriously, though, is Summer missing the contacts or are you just wanting to teach 2o2o for the heck of it?
I think the way some people in my club taught it was that they got a target - brightly colored little plastic disk, like the red lid from a treat canister - and taught the dog that really smelly treats would be on the target. The dogs then learned to look for the target at the end of the contacts, getting your 2o2o. Eventually then you'd fade the treats and then fade the target altogether. I haven't tried it, but they seemed to get decently good results.