In case it isn't fleas (though it does sound like dried-blood flecks and poops that fleas leave behind) it could also be that he has a rash that is scabby. My cat gets feline acne on his chin, and the residue looks like black dirt.
If it is fleas and you put Frontline or Revolution on him (again, these are veterinary products, don't use Advantage, it is terrible for the kitty's system), one good thing about cats is that they are warmer than humans, so they draw the fleas out of the environment. If they have Frontline in their skin, and the flea bites them, the flea dies. So along with vacuuming and washing the blankets and all the rest, kitty becomes a walking flea-removal machine for you.
If you do determine it's fleas, sometime also take a stool sample to the vet to be sure that kitty doesn't have tapeworms.
hi and welcome Felix...and kitty. sounds very much like fleas to me..even tho he is an indoor kitty, its still possible. I will send you a slide show that will give you an idea what they look like, and some tips on how to clean the house and bedding...after you've treated kitty with a product from your Vet...always get the ones from a clinic and NOT over the counter...these can be dangerous.
http://www.medicinenet.com/script/main/art.asp?articlekey=107386
http://www.simplesteps.org/greenpaws-products#/h/+/+/+