pafarmgirl, I do all sorts of things to occupy my birds like your hanging apples idea. I have a suet feeder that I stuff with nutritious treats such as leafy greens, cabbage, apples, melon, etc. I have Flock Blocks that I put in during the bad weather, and I have "chicken trees" for them to fly up in, and spend time in during the day, etc. So, I doubt the pecking is a symptom of them being bored, but I could be wrong. It just looks wrong to them, I think, fo ra comb to have black tips, which is why they are pecking (out of curiosity).
My boy has only lost ONE tip...it's taking FOREVER for the dead parts to fall off. He's going nuts being inside 24/7, but I did put a girl in with him that is much shorter than he is so she can't reach his comb, and she's not as curious as the others, either. It's working out great in that respect. I have him in a horse stall that is 12x24, so plenty of room for the 2 of them, and I've been giving them fun snacks and things to do, but I can tell he's bored. Poor boy.
Chickorama - I DID coat his comb, every 2 days, through winter. He still got frostbitten, unfortunately.