Most of ours are very easy to pick up and hold, so we put a few handfuls of DE in a floppy rubber garden bucket, hold the girl with her head under one arm, and just rub a bunch of dust all over her butt and into any other loose-feathered areas we can reach. We've tried putting dust in a paper grocery sack, putting the whole bird inside with just the head sticking out, and shaking the bag gently, but that's more trouble than necessary. If yours are hard to catch, I would think you could use the first method after they go to bed in the evening. Ours have plenty of dusting areas available almost year-round, and most of them are good about keeping the mites down by themselves, but now and then one or more of them don't keep up with the bathing, and the mites can take off. From the research I've read, the sulfur dust is MUCH more effective at killing off the mites and keeping them from reappearing for a lot longer. According to that research, common clayey garden dust is just as effective as DE. I've been putting about a half-cup of sulfur in each of their dust pits, a few times per year, and more if we have a current mite problem. As I've posted earlier, the sulfur dust is entirely non-toxic, actually edible and not even harmful to breathe in small amounts. It'll get your clothes a little smelly if you're not careful, but that's not a big deal. In contrast with DE or regular dirt, apparently a dust bath containing sulfur can help get rid of mites in non-bathing coopmates as well. We got a big spray bottle of a permethrin/pyrethrin solution a couple days ago at the feed store, and sprayed it into the likely mite hiding/breeding places in the coop, like cracks, weathered wood, etc.. That seems to be pretty low-toxicity stuff, derived from chrysanthemums. Since we've been using all these methods at once, or overlapping, it's hard to say how effective each of them are. Since the mites are carried by wild birds, it's hopeless to get rid of them permanently, short of cooping the chickens up full-time in a sealed sterile room. If I were you, I'd get all three of the weapons mentioned above, and use them several times per year. Do you have some good, dry soil areas for them to dust bathe in? If your girls are getting visibly itchy, they probably have a bad infestation. Ours are cuddly lap birds, so usually the first sign of trouble is a bunch of itchy bites on ourselves. Good luck!