My egg stain was quite large. The egg stain was about 18 feet up the side of the house, about 24” wide at the top and had dripped down the siding about 60”. It was about 2 months old and it had turned black on the white vinyl siding.
I had read several articles online about removal of egg stains, but they all seemed to take what seemed like an excessively long time to dissolve the stain (especially 18 feet in the air on a latter)! So decided to try an old spray bottle of Westley's White Wall cleaner I still had on the garage. And it worked extremely well!
I sprayed the cleaner on, waited about a minute (just like on whitewalls) and then used a small scrub brush to loosen the stain. It took only a minor effort to get down to the siding even in the thickest areas. Where the egg stain was not as thick it just dissolved it when I sprayed it on.
Finally, I got out the water hose and washed the area off...and all the stain was gone! I only wish I had thought about using whitewall tire cleaner sooner.