You should be able to clean it. Do what you can to avoid pulling out a brush. Hot pbw does wonders. You could also try some kind of recirculating pressure washer. Like the one more beer started selling.
Don't take any more faith in anything I say than you would anyone else on the internet. If you listen to what I say, then hurt your self or break something it is your own fault, I am just expressing my opinion or experience.
THINK for your self!!