Little teapots with long spouts have become a fixture in many homes for reasons that have nothing to do with tea.

Called neti pots, they are used to rinse the nasal passages with a saline (salt-based) solution and have become a popular treatment for congested sinuses, colds and allergies, and for moistening nasal passages exposed to dry indoor air.

The FDA has concerns about the risk of infection tied to the improper use of neti pots and other nasal rinsing devices. The agency is promoting safe practices for using all nasal rinsing devices, which include bulb syringes, squeeze bottles, and battery-operated pulsed water devices.

These devices are generally safe and useful products, but they must be used and cleaned properly.

Most important is the source of water that is used with nasal rinsing devices. Tap water that is not filtered, treated, or processed in specific ways is not safe for use as a nasal rinse.

Some tap water contains low levels of organisms, such as bacteria and protozoa. These include amoebas, which may be safe to swallow because stomach acid kills them. But these “bugs” can stay alive in nasal passages and cause potentially serious infections, according to the CDC.

The procedure for nasal rinsing may vary slightly by device, but generally involves these steps:

•  Wash and dry hands. Check that the device is clean and completely dry. Wash the device with distilled, sterile, or boiled and cooled tap water. Then dry the inside with a paper towel or let it air dry between uses.

•  Use the appropriate water to prepare the saline rinse, either with the prepared mixture supplied with the device, or one you make yourself with distilled or sterile water, which you can buy in stores. The label will state “distilled” or “sterile.” Boiled and cooled tap water—boiled for 3 to 5 minutes, then cooled until it is lukewarm may be used. Previously boiled water can be stored in a clean, closed container for use within 24 hours. Or use water passed through a filter with an absolute pore size of 1 micron or smaller, which traps potentially infectious organisms. CDC has information on selecting these filters, which you can buy online or from some hardware and discount stores.

•  Lean over a sink, tilt your head sideways with your forehead and chin roughly level to avoid liquid flowing into your mouth.

•  Breathe through your open mouth.  Insert the spout of the saline-filled container into your upper nostril so that the liquid drains through the lower nostril.

•  Clear your nostrils, and then repeat the procedure, tilting your head sideways, on the other side. Some people like to do this procedure in the shower.

Nasal rinsing can remove dirt, dust, pollen and other debris, as well as help to loosen thick mucus. It can also help relieve nasal symptoms of allergies, colds and flu.