Harry,
Buddy's right. The "old timer" is wrong. I catch loads of stocker trout on flys. That's the only way I fish for them. Buddy has given you really good advice. I might add that stocker trout almost immediately start feeding on whatever is available in the water they are stocked in. It doesn't take them long to adjust and begin to act a lot like a wild trout. One thing I've found very effective on stockers many times is a soft hackle stripped very fast especially if you see some surface activity. I like partridge and orange or partridge and green.