hi marizydotes, ronseal decking cleaner(about � 8:99) it brings up decking brilliantly,use a stiff yard broom and give it some serious elbow grease then slouse down with a hose,leave for 24 hour's to dry(you need a couple of dry days for this) then seal the wood with a ronseal decking stain,this is about �19:99(clear or stained) but it is a good product ,again you need 24 hours of dry weather...if your lucky..it really do'es come up like new....and no i do not work for ronseal,these were the instructions given to me by the joiner/carpenter who fitted my decking 4 years ago and have proved to be invaluable as my decking stil looks great ,he said allthough the wood is pretreated for water becuase we live in a 'wet' climate you still have to maintain it and if i did this each year my decking would last 15/20 years..i don't know about that but i do live in the west of scotland and we have a lot of rain but it just run's of the surface of the wood like wax ,hope this help's