Possible Clues:

• Scrub, with a tree
• So to make 'er come clean is to make 'er mext thing to a nut
• See 19-Down
• That did be the capital of Holland in the water
• Used to be hard to wake
• Norfolk water used to be the start of 12
• Clean area of the English coast
• Get into a lather
• Used to be the capital of Holland but is now off England
• It is often hampered?