John,
Froggy said it right. Sometimes, a member will post findings of a recently purchased, used air gun, full of green, slimy goop and corrosion. This is what water does, and why we all try desperately to keep it out. First, check to see if your Omega has a water separator/filter installed. Second, SEARCH forum "Compressor Section" for Yong Heng compressors. You'll see posted pictures of how members have set-up their compressors using in-line filters. They are usually 12" long, gold aluminum tubes which contain a plastic insert with drying beads, charcoal and cotton inside. Ebay and Amazon sell them from $55 on up. They attach with male foster fitting on one end with female on other. There are less expensive in-line filters, that just use cotton inserts, but most use these in concert with the gold one. I hope this helped.
WM