Serious poultry breeders who exhibit their birds have been bathing and grooming them for decades. Although the head is often much trickier to work on than the rest of the bird, it's basically as you suspect. Attention to delicate areas with a moistened washcloth or Qtips is about the only way to get then clean. You can also pull any severely caked feathers and allow them to grow back in.

I've had to wash chickens in the kitchen sink using warm water, a wet paper towel, Qtips and some baby soap, which is as harmless as water. :) I'm not saying they APPRECIATED it, mind you...the key is the soaking the grimy feathers need, which sometimes need to be trimmed away anyway with scissors (not near the eyes though). Do this on a warm day out of drafts, which can cause chilling. Rinse them really well and have some old towels ready to dry the birds (those feathers hold a ton of water!) and a hair dryer set on 'low'. My birds have always loved the hair dryer once they got over the initial noise of it, but if you use one keep your other hand on the bird to fluff the feathers where the air is directed so you don't roast it's delicate skin.

Have fun~ :)

Velvet ~:>