Passage: Edward Murdstone – The main antagonist of the first half of the novel, he is Young David's cruel stepfather who beats him for falling behind in his studies. David reacts by biting Mr Murdstone, who then sends him to Salem House, the private school owned by his friend Mr Creakle. After David's mother dies, Mr Murdstone sends him to work in his factory in London, where he has to clean wine bottles. He appears at Betsey Trotwood's house after David runs away. Mr Murdstone appears to show signs of repentance when confronted by Copperfield's aunt about his treatment of Clara and David, but when David works at Doctor's Commons, he meets Murdstone taking out a marriage license for his next young and trusting wife.

Question: What was Mr Murdstone's job at the factory he worked at in London?
clean wine bottles