Let’s say this happens to you. A bird frequents your dish, and when he does, he leaves a little bit behind. Over time, this builds up and you begin to think that it’s affecting your signal strength.
Sure, you could replace the whole dish but that seems a bit extreme. So how do you clean it?
The first thing to do if you find yourself in this situation is to mark the position of all alignment screws on the dish. If you accidentally knock it around, you’re going to want to put it back. Use a pencil to make precise marks that will help you get that dish back into place… remember that a difference of 1/32″ could mean you’re aiming hundreds of miles off target.
When you’re cleaning, try to avoid touching the LNB (the front part) at all, not with water and not with chemicals. This is the most sensitive part of the dish and can be easily damaged.
Now, if you must use some sort of cleaner, use something that promises to dissolve, um, “animal matter” without damaging metal. Heavy duty windshield cleaner is a good choice, and some of that green kitchen cleaner is also pretty good. Pour or spray the cleaner on the dish gently and let things soak for a while. Then, use a bucket of water or a hose with the gentlest possible pressure to rinse the dish. You don’t want to move the reflector from the force of the water. It might take a few tries but hopefully all of the “stuff” will come off.
If you need to scrub, use a soft sponge recommended for non-stick surfaces. Don’t ever use anything abrasive and certainly not steel wool. You’ll damage the coating on the dish and then you have to repaint it.
That should be all it takes… just be careful and cleaning the dish should be easy.