Nonsense! If you want to use this analogy, it would be more appropriate to say that after taking the shower, you then put freshly-laundered underwear on your freshly-washed body, as opposed to buying new underwear and tossing it after wearing it once.
For mechanical filtration I use the material below from Swiss Teopicals, and have been using the same panel for over 5 years.
Hello; I expect some pushback. There are some distinctions to be considered. One being I do not toss filter parts which can be reasonably cleaned. Using the analogy to underwear laundry, I would consider tossing worn undies if the poo could not be cleaned out. So if the filter material is sturdy enough to stand a decent cleaning I do reuse it.
I suppose the stuff I toss is possible to clean, but it would take much more than a gentle sloshing around in old tank water. Also, the sheet material I use is not all that sturdy. Maybe could survive a decent cleaning or two. But such is not the main point I tried to make.
My take is the majority of the detritus captured by the floss is fish poo. A popular opinion posted many times over the years on this forum is to "gently" rinse used filter floss & similar filter material in a bucket of tank water. During a WC e collect the old tank water in a bucket then gently slosh the loaded filter material in that bucket of water. Sure such will dislodge some of the poo, but not all that much. Put such a rinsed filter panel back in the filter and it will still have load of poo and other detritus.
Now the stuff duanes posted looks to be sturdy. Looks to still be in good shape after five years. I will guess it holds up to more than "gentle " sloshing. Correct me if such is wrong. I would consider that material as cleanable.
The point, as I understand, it over the years is a fear aggressive cleaning or the tossing of filter floss disrupts the colonies of bb (beneficial bacteria). That since the bb are needed to maintain a "cycled" tank such tossing or cleaning is a no-no. Such an idea leaves out the fact the bb colonizes many surfaces throughout the tank.
Ther could be some bb lost with the floss to be sure. An important point, to me, is there will be much more on other surfaces. The bb colonies are sesile which means they "stick" to solid surfaces. My understanding they stick well. I keep the plastic frame of my filters and throw away the floss which wraps around the frame. The bb ought to stick on the frame. I do not normally scrub the filter body, impeller and tubes so the bb colonies are left intact on those surfaces.
In addition, we can add solid structures in filters & sumps which allow the bb places to live. In the 1970's I used marbles among other things.
Let me rehash the main point. The main reason, as i understand it, to gently rinse loaded filter floss is to preserve bb colonies. I have not read of some benefit of keeping a portion of fish poo around to put it back in the tank. We each get to run our tanks any way we want. i have been tossing poo loaded filter floss for well over fifty years so far. I take care to not toss the floss and to scrub a filter body and parts at the same time outside some emergency.
I often keep a sponge filter running full time which I can toss into a tank. Sometimes I bury the sponge filter in the gravel and keep it running with an air pump.