Do you already know that the cats won't eat the chicken, or just anticipating it? I would think that strays would be pretty used to eating birds, mice, etc. and find raw chicken an acceptable meal on its own. Otherwise, I think yingying's suggestion are good. Tuna water is pretty standard for making food "smellier," and thus more interesting to cats.
I'm not sure what you can do with it raw. You could cook it and then strip the bones off, I think that's what I'd do, since the cats are getting kibble most of the time it's probably best to stick to cooked foods... however, I'd also think if any are hungry enough they'd eat anything so you shouldn't worry too much, the cats that really are hungry will eat them.