Most reusable coffee filters last for 3 to 5 years or even longer depending on how much use they get and how well kept they are and cleaned.
When using a reusable coffee filter you don't need a paper filter on the reusable filter unless the coffee grinds are too fine and go through the filter.
Most ground coffee is ground to the proper size to work with reusable coffee filters but if you have a really fine grind of coffee and it falls through the reusable filter then using a paper filter inside of it is okay.
Reusable coffee filters are designed to be rinsed, washed and reused several times before needing to be replaced.
A reusable coffee filter only needs replaced once it wears out or comes apart or if it has mold on it that won't wash off.
You can rinse a reusable coffee filter out in the sink.
After making coffee with the reusable coffee filter, simply dump the coffee grounds out into the trash and then run the reusable coffee filter under the sink in cold or warm water.
Getting some of the used coffee grounds down the sink drain is okay and won't clog your sink.
You can also place your reusable coffee filter in the dishwasher on the top rack to wash it.
Most times though a reusable coffee filter simply just needs rinsed and doesn't require any soap unless it has been left with old coffee grounds and grown mold.
Reusable coffee filters can save you money by not having to buy the paper filters all the time.
Reusable coffee filters can last several years depending on how much coffee you make and most often the reusable coffee filter will outlast the coffee maker itself.