engine cleaner help. and suggestions please

when i used to recondition used cars , i would get the engine bay wet , then spray with citrus cleaner, let stand about 10 minutes, and hose off. granted the cars were usually less than 5 years old, so it did a great job on them. at home i use simple green (same method) and it does pretty good. i have tried stronger degreasers and have found that it ruins the engine paint by fading. i usually just get a plastic shopping bag and wrap it around the distributer the best i can.