dear enam bhai
i used 3m apc for enginebay cleaning, its also all purpose cleaner like turtle presoak
pls ref page #10 , posts # 185 ( bilori's open heart surgery ) and post #196 on same page for pics, tools used in opration, step by step opration
enam bhai its true to reach some nooks and corners its difficult but sir muhabat main mushkalat tu hoti hain na
i had hurt my hands and fingers many times in such type of oprations hehe btw try some long arm brushes from metro or hyperstar khi , thoes would be helpful in such cleanings 