Not useless, actually very good for more than just parasites:
The first recorded use of Cloves is by the Chinese TCM in the first century B.C. Cloves kills intestinal parasites and exhibits broad anti-microbial properties against fungi & bacteria, thus supporting its traditional use as a treatment for diarrhea, intestinal worms, and other digestive ailments.
Cloves is also known by the names Clavos, Clovos, Carophyllus, Caryophyllus, Ding Xiang, and Lavanga. This herb is native to the Spice Islands and the Philippines, but also grown in India, Sumatra, Jamaica, the West Indies, Brazil, and other tropical areas.
The word Clove is from the Latin word "clavus", meaning "nail", in reference to the shape of the buds. The genus name Eugenia is named after Prince Eugene of Savoy (1663-1736). The first recorded use of Cloves is by the Chinese in the first century B.C. During the Han Dynasty (207 B.C. - 220 A.D.), court visitors were required to hold Cloves in their mouths when addressing the emperor, so as not to offend with bad breath.
Folklore says that sucking on two whole Cloves without chewing or swallowing them helps to curb the desire for alcohol. Traditional Chinese physicians have long used the herb to treat indigestion, diarrhea, hernia, and ringworm, as well as athlete's foot and other fungal infections.
India's traditional Ayurvedic healers have used Cloves since ancient times to treat respiratory and digestive ailments.
The medieval German herbalists used Cloves as part of anti-gout mixture. Early American Eclectic physicians used Cloves to treat digestive complaints, and they added it to bitter herbal medicines to make them more palatable. They were also the first to extract Clove oil from the herbal buds, which they used on the gums to relieve toothache. A few drops of the oil in water will stop vomiting, and an infusion will relieve nausea. Essential oil of Clove is effective against strep, staph and pneumomocci bacterias.
Contemporary herbalists recommend Cloves for digestive complaints and its oil for toothache. Cloves is used to make vanillin, which is artificial vanilla. Much of the world's production of Cloves goes to making Clove cigarettes, such as Indonesian Kretaks for their stimulant action.
The familiar Cloves used in the kitchen is the dried flower bud. The primary chemical constituents include eugenol, caryophyllene, and tannins. Cloves are said to have a positive effect on stomach ulcers, vomiting, flatulence, and to stimulate the digestive system.
It has powerful local antiseptic and mild anesthetic actions. Cloves contain sesquiterpenes which have been shown to have significant activity in inducing the detoxifying enzyme glutathione S-transferase in mouse liver and small intestine. Japanese researchers have discovered that like many spices, clove contains antioxidants. Antioxidants help prevent the cell damage that scientists believe eventually causes cancer.
On the other hand, in laboratory tests, the chemical eugenol, has been found to be a weak tumor promoter, making clove one of many healing herbs with both pro- and anti-cancer effects. At this point, scientists aren't sure which way the balance tilts. Until they are, anyone with a history of cancer should not use medicinal amounts of Clove. For otherwise healthy non-pregnant, non-nursing adults, powdered clove is considered