I use the sponge (ordered the mitt but didn't arrived yet). For production, I follow the guidelines proposed by Mike Phillips on previous answer.
What I do like to use as lube 'when claying a wet car' is car shampoo at a medium dilution on a spray bottle (like a quick detailing spray, but with soap). It works really well, and a little goes a long way.
I rinse each section just after when claying with shampoo. This practice has some inconvenience like keeping the car always wet until final rinse and dry.
However, once you dry, you have the cleanest clayed car ever!
On a dry car, I use those sponges with Meg's Final Inspection 34 (the lube I have in gallons).
With the mitt I pretend to maintain the wet car claying habit, although with better grip and larger surface area. The suggested ONR method looks really interesting.
After using clay pads 6' and the autoscrub sponge, I still don't know why those mitts aren't as popular as they should be... May the High Price be the answer?
Used Black Friday discount to get mine.
Kind Regards, good luck.