The rotating bristled roller in the head of many upright and power-head vacuum cleaners, which beats and agitates the pile to loosen dirt. On a hand-knotted rug it is too harsh: it beats the pile down and can grab and shred the fringe, which should not be vacuumed at all. The recommended alternative is suction alone from a light canister vacuum whose head has no beater bar, passed side to side across the rug's width rather than lengthwise against the pile; if only a beater-bar machine is available, the bar should be switched off.
Various techniques for cleaning carpets, including hot water extraction (steam cleaning), dry compound cleaning, bonnet cleaning, and encapsulation, each suited to particular carpet types, soiling levels, and drying times. Hand-knotted rugs need gentler care: side-to-side vacuuming with a canister vacuum whose beater bar is off, sparing the fringes; an occasional light wipe with diluted, bleach-free dish foam on white cotton towels, worked in sections along the pile so it dries within about an hour; and a professional wash every 5 to 10 years, every 3 to 5 in heavy traffic, and before storing a rug for a year or more.