Product review (5 stars): Amazon carries great Watts products.
Watts OS process works great, but drain from flushing filter became plugged and drain water flowed out air gap. Had to remove , clean tubing, restore. When it worked, it made a loud gurgle sound dropping into trap.

This fitting solved both problems, but be careful - at some point in its run, the dishwasher drain pipe MUST be higher than the connection at the disposal. Otherwise, the OS drain water flows back to the dishwasher, which may have its own air gap - you'll have a flood at the dishwasher location!

Read IMPORTANT at end of Watts instruction sheet for adapter!
Bob