<span style="font-family: trebuchet ms,geneva; font-size: medium;">I never wash cloth vacuum cleaner bags in a washing machine and in fact try to avoid washing them at all because doing so causes the pores to close up, especially if the cleaning agent (soap or detergent) is not thoroughly rinsed out. This obviously will impede air flow and thus cleaning efficiency. </span>
<span style="font-family: trebuchet ms,geneva; font-size: medium;">The only time I will wash a bag is if it came from a household with smokers or stinky dogs, or when something nasty was vacuumed up. I'd rather have a bag that smells a bit musty than to risk ruining it by washing it.
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<span style="font-family: trebuchet ms,geneva; font-size: medium;">When I do need to wash a bag, I hand-wash it in cold water with a little Woolite, not too much, to facilitate thorough rinsing and then to rinse several times in cold, clear water, wringing the bag out somewhat but not too tightly. </span>
<span style="font-family: trebuchet ms,geneva; font-size: medium;">I never machine-dry them, either. The heat will shrink the fabric, possibly to the extent of causing the bag to get so small that it will longer fit, and again, will definitely cause the pores to close up. Line-drying is the best. </span>
<span style="font-family: trebuchet ms,geneva; font-size: medium;">After washing and drying, I give the bag a thorough vacuuming inside and out with my bag cleaner to open up the pores.</span><span style="font-family: trebuchet ms,geneva; font-size: medium;"> You really do need to give the bag a good "pounding" to open up the pores. </span><span style="font-family: trebuchet ms,geneva; font-size: medium;"> However, since I don't have access to my bag cleaners at the present time, I would have to use an upright with an agitator. Obviously, you would want to be VERY careful and pay close attention, lest one of your fingers or knuckles get mangled by the agitator brush.</span>