Here is useful way to spray paint or other liquids which are only supplied in bulk. This is a 16 oz. disposable/washable bottle with a spray unit which screws on the bottle. The aerosol unit is quite long lasting = certainly a couple of spray outs of a muffler.

One use is to spray our exhaust paint which we supply in a quart can. You may want to thin any paint about 10% to be sure the sprayer will not clog with heavy solids. In fact, light coats on a 356 or 911 muffler will give a better cure with heat cycles.