If you could keep them warm and dry them up you could carefully give them a bath or wipe them down. I just gave up with my white birds... they are now brown and yellow tinted.
Sorry to say it only gets worse with age. My ameraucana (who is pure white) was dust bathing today in the rain. She's covered from head to toe. I asked her how she planned on getting clean and she just gave me a look.
Whats with the yellow tinting?? course we have the same problem with the horses and there white manes and tails.. I think you are right though.. let them have fun and just be chicks :O)
I don't really have a problem with my white chickens other than their foot feathers. I'd just take a warm wash cloth and wipe the chick off. Make sure he/she doesn't get too cold though!
HAHAHA.. nope we are in Spokane and no issues yet though the hubby just said a strom is headed our way next week its supposed to rain all week!! BUT we can sure use it :O)