I tried last night for HOURS to make one work... I finally got it! I've seen the Mazzei and it's not nearly as efficient as that, but I'm getting bubbles and I threw a stone in it as well... it's foaming, so I presume I'm making progress. Here's the basics:
Cut a 12" length of 1/8" stiff tube at a 22 1/2 degree angle... Drill a 1/8" hole in the 1/2" PVC and insert the tube so it's 3/4 down the diameter of the pipe. I placed the whole 2" before the pipe enters the skimmer. I'm using a Mag 5 to power it and running almost full throttle through the skimmer.