Perchloroethylene and its relatives are now the dominant solvents used in dry cleaning. Cabon tetrachloride has been banned for use in dry cleaning in most countries.
Carbon tetrachloride is vicious stuff. It can cause liver, kidney, and central nervous system damage - the liver enlarges and its cells are usually destroyed.
Exposure to carbon tet, can make you feel as if your seriously drunk with dizziness, vomiting and a need to sleep. Repeated exposure leads to brain damage and death.
It can cause dermatitis (one of the reasons why its rare to find it in dry-cleaning) and is dangerous by inhalation as well as ingestion. It's also usually regarded as a probable carcinogen.