Thank you for your comments but I honestly don't have the heart to do that. I feel really sorry for my roost that I just can't do much for him. I think I will take it to the vet cause I won't be able to clean it cause it has blood crust and I think if I take it off to clean it will hurt and bleed a lot. It's on his tail on the very back, don't know how to explain.in the puffier part of his tail
If I clean it with saline and take out any bug if he has. Do you think he will get better soon???@Wyorp Rock
Taking him to the vet would be your best option, since you are having trouble treating him. It most likely will hurt, so if you can't do it, then you will have to rely on someone like your vet to do it for you.
To me it looks like it is infected, so he needs care. I know you are trying to help him, but flushing with saline will only get you so far. You may have to debride the wound, it's hard to say, and that would involve scrubbing and making it bleed. So if you have a vet that would be great.
If he has mites, then the vet should be able to help you with those too.
Here is a link so you can search for an Avian Vet, they should be the most knowledgeable in bird health, if no one is in your area, use the vet you normally use.
http://www.aav.org/search/custom.asp?id=1803