The raids involved staff from the National Crime Agency
Vulnerable eastern Europeans were trafficked to Plymouth and ordered to live under the stairs "like some grotesque Harry Potter concept", a court has heard.
The victims, mainly from the Czech Republic, were brought to the UK and forced into compulsory labour by a gang based in the city.
Plymouth Crown Court was told they had to sleep on the floor or in a garage, urinate in bottles and eat outside.
The defendants deny all charges.
Malcolm Galloway, prosecuting, said the victims were used as house servants, cleaning the house, car and cutting the lawn.
He told the court how a neighbour, Claire Pinnock, told police she saw Petr Tancos standing by and directing one of the men to cut the grass with a kitchen knife.
She described the men as generally malnourished and unkempt.
The defendants are:
Ruzena Tancosova, 34, of Union Street - charged with conspiracy to traffic for the purpose of exploitation, requiring a person to perform forced or compulsory labour and acting as a gangmaster
Petr Tancos, 35, of Ford Park Road - charged with conspiracy to traffic for the purpose of exploitation, requiring a person to perform forced or compulsory labour
Nela Dzurkova, 26, of Ford Park Road - charged with conspiracy to traffic for the purpose of exploitation
Martin Tancos, 35, of Saltash Road - charged with conspiracy to traffic for the purpose of exploitation and acting as a gangmaster
Katerina Kurejova, 35, of Saltash Road - charged with conspiracy to traffic for the purpose of exploitation
Police originally arrested eight people in September but the prosecution offered no evidence for the other three and not guilty verdicts were offered.
They are: Lenka Cmejlova, 32, of Union Street, Jiri Sebelik, 37, of Union Street and Sandra Tancosova, 25, of Flora Court, Plymouth.
Mr Galloway said the defendants would use threats of violence of "a few slaps" if they did not do what they were told, or a "punch to the face" if they were being rude.
The court heard a financial investigation into Ms Tancosova found between the period 1 January 2010 and 16 September 2014 she received a total sum of £86,517.25 in benefits.
She had four bank accounts with the credit turnover for the accounts, including benefit payments, amounting to £148,923.27.
The trial continues.
