[[Image:straining icon.png|right]]
[[Image:straining with cloth.jpg|thumb|right|250px|A woman uses a sari cloth to strain water. Photo: CAWST.]]
Straining water through a cloth has been widely used for household water treatment in many cultures for centuries. A common sari cloth is usually used for this in South Asia, for example (photo on right). Straining through a fine cloth can take out guinea-worm, organic matter, and help clear up turbidity. Such cloths are effective in straining out the copepods in the water. These tiny water creatures act as intermediate hosts for the larvae which transmit the disease. Some guinea-worm eradication projects supply a large-diameter drinkingstraw with a filter mesh on one end so that
copepods are strained out when water is sucked up the straw.
Monofilament nylon cloth has been found to be more effective in straining out the vector - various species of the small crustacean, cyclops - than local cotton cloth, though the former one is more expensive.
The pore size range in old (laundered) sari cloth is 100–150 μm, but about 20 μm if the cloth is folded four to eight times. The holes allow water to pass but retain particles and pathogens >20 μm. Straining through sari cloth has been shown to be effective in filtering out the plankton to which cholera bacteria may attach themselves, therefore reducing the risk of cholera. This simple method can also filter out many helminths and their eggs and larvae.
* Brikke, François, and Bredero, Maarten. ''[http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CC0QFjAB&url=http%3A%2F%2Fwww.who.int%2Fwater_sanitation_health%2Fhygiene%2Fom%2Flinkingintro.pdf&ei=cwJpT-zaO-OiiQKCst2rBw&usg=AFQjCNEWOQhTgF3a7lzhuw5OA2KmbVGxcA&sig2=Rt2EURUyGVqDcwFg6p0xAw Linking technology choice with operation and maintenance in the context of community water supply and sanitation: A reference document for planners and project staff]''. World Health Organization and IRC Water and Sanitation Centre. Geneva, Switzerland 2003.
* [http://www.lboro.ac.uk/well/resources/technical-briefs/58-household-water-treatment-1.pdf 58. Household water treatment I]. WATER AND ENVIRONMENTAL HEALTH AT LONDON AND LOUGHBOROUGH (WELL).
* [http://www.tulane.edu/~trmd700/nbaker.pdf Acceptance and use of communal filtration units in guinea worm eradication.] Tropical Medicine and International Health, January 2000.