any one use spawn sacks when fly fishing for steel head.
No. That would be bait fishing. If you want to use an egg pattern, many are available. They are called "beads", are made out of plastic and have a small hook embedded in them. You can run them in any number of pattern variations. While this an effective way to catch a steelhead, it is generally frowned upon as a lowblow method.
Swinging up a steelhead is the generally accepted method, esp on the big rivers in the west. This method essentially involves swimming a minnow imitation within close proximity of the steelie and getting a hard hit from a predatory fish. Fishing this way ensures you get a fresh fish, as those worn out by spawning are loath to work very hard for food. It also means it wont be as productive.
On rivers where there are lots of wild fish that will survive spawning if given a chance, there are ethical considerations involved btw lining fish with beads and swinging them up. A fresh fish is much more likely to survive a catch and release than one half in the bag from spawning. Im guessing all the fish on your local waters are stockers, so they arent going anywhere anyways, but if you do have wild fish in the mix, keep this issue in mind.
Google "swinging" or "beading" for steelhead and you should get a bunch of youtubes and other sites that will give you more specific info on these techniques. Good luck!