You do NOT need a double hook for drifting bait. Period. Because the cowlitz boys do it does not mean it is the gospel.

Here's the way I see it; in medium to low/clear water conditions like you and I like to fish, we are drifting bait on #2 or #4 hooks (I use 4's 90% of the time). Lead used will be light for a delicate, finesse presentation. I ususally fish straight bait or bait and yarn. When the offering is coming towards the fish and it looks enticing, the fish is trying to eat it plain and simple. #4's are so small that often the fish does not feel the hook until well inside it's mouth. By then, it's too late for the fish-you got em! It only takes 1 hook. 2 hooks is overkill and a waste of money.

An additional note on the cowlitz boys double hook infatuatiuon. I've observed from fishing down there over the years that when one person does something different and has some success, everyone drops what they use and rushes to use the "new technique" forgetting what they were using worked perfectly well. Someone down there decided that summer fish would only bite a double #4 with a tiny red corkie in the middle and a bit of egg on a 6 ft. leader. It works but at the same time it's laughable because it's overkill. We are fishing beside these guys using a good old single #4 gammie on a 3 ft. leader with straight eggs and doing just as well. The same rig we've used for a decade.

In summary: Theres no reduction in effectiveness with double hooks but there's no huge advantage either. Save some money and get twice the milage out of your hooks-fish a single.