Possible Clues:

• Told to get a bucket of steam from a sucker with small job (1,4'1,6)
• American cons taken to task for sending the newcomer for the bubble in the spirit level (1,4'1,6)
• American idiots taken to task for sending the newcomer for the bubble in the spirit level (1,4'1,6)
• Area with a type of gold taken to task for getting the newcomer to order the striped paint (1,4'1,6)
• Idiot found covered in arsenic taken to task for looking for a bucket of steam (1,4'1,6)
• Looking for a bucket of steam is key to 21 across - and that's the message (1,4'1,6)
• Task for a jester wasted effort
• Looking back, Davenport draws attention inside mission by sending someone for bubble in spirit level (1,4'1,6)
• Initial April Fool's assignment to send someone for the bubble in the spirit level (1,4'1,6)