Pecking is a management issue. When chickens get bored, are crowded, or are being fed incorrectly, they peck each other. Once they draw blood, and once they get into the habit, it is very hard to stop. Do use the blu-kote. If you can identify one hen that is a bully, remove her for 3 days. Sometimes, when you put her back after a break, she'll be lower in the pecking order. Meanwhile, do you have a minimum of 4 square feet per hen inside and another 8 square feet outside? Do you have inside and outside roosts? Feeders that aren't crowded? Places to dust bathe? Is most of their feed intake laying hen pellets? Do they get greens or are able to free-range? Do they get free-choice oyster shell? There are many variables! Once in awhile I've had feather picking here. A little readjustment of the management and the problem disappears, so, it can be solved. Good luck!