I used to be an oiler on a crane. One of my jobs as an oiler was to grease the machine. One particular time I had to crawl underneath the machine and grease the under-carriage. When I finished, about a 1/2 hour later, my arms were covered in grease all the way up to my elbows.
When I went to go clean up I could not get that grease off my hands and arms. No matter how hard I scrubbed I could not get it off. Finally I found "The Special Soap" that could get it off.

If we tried to wash our sins away. No amout of scrubbing would do it. No matter how hard we scrubbed we would never be able to wash away our sins. If we look to Jesus, and what he did on the cross. You see Jesus died on the cross for our sins. He paid the price. The shedding of His blood washed away our sins.
We need to remember what Jesus did on the cross for us. Allow Him to be that "Special Soap".