From the Cunard website -
"Specialist cleaning services
Wet cleaning is a professional, aqueous cleaning process for sensitive and non-washable garments. The wet cleaning process was invented in 1991 by Kreussler & Co GmbH in cooperation with Miele. Wet cleaning avoids the use of chemical solvents. Environmental groups and the United States Environmental Protection Agency have indicated that such alternative ""wet cleaning"" methods are better for the environment than chemical solvents and proponents of wet cleaning state that these methods can be used without shrinking or otherwise damaging garments that typically require dry cleaning.
We also offer slight alterations / repairs on board, for an added cost."