The average established tank with a system that employs bio-media is in balance and the colonies of Nitrobacter are in equilibrium with the production of wastes in the system. Removing 50% of the media and killing off perfectly good bacteria with the intent of recovering lost surface area for them to re-establish and repeat the hypothesized plugging of the pores within 30-days sounds like busy work or a great way to keep bio-media manufacturers in business.
When these bio-media where introduced to the hobby 40+ years ago, a key selling point was their durability, ease of cleaning, and reusability. I know, because I worked in a LFS at that time and that is how Kordon and the others pitched them to shop owners. Enterprising shops even offered to "prime" the media by dropping them in store tanks for a few days before customers placed their "seasoned bio-media" in their own systems.
Perhaps the most salient question has not been asked. Is there a demonstrable benefit to implementing this chemical cleaning regimen, and if so is it any better than cleaning by agitation?
Without an electron scanning microscope, it would be difficult to determine if chlorine or other chemicals are actually flushing out the detritus and Nitrobacter, or if the process is simply killing the bacteria in place and leaving the pores plugged.
Using standard aquarist test kits, I have found no measurable drop below pre-bio-media-cleaning levels of ammonia, nitrite, or nitrate in the hours or days after replacing or bleaching 50% of bio media. However, I have seen non-lethal climbs in waste levels for short periods post-sterilization or replacement.
What I have observed is that vigorously tumbling 100% of the bio-media in a bucket or hitting it with a power washer breaks free visible detritus and there is no measurable post-wash climb in waste levels when it is returned to the filter in a timely fashion.
I think it important to note, that bio-balls and similar media where introduced as cheap alternatives to the ceramics and promoted as not "plugging" as you have outlined. In the last 40 years, I have had to periodically replace the plastic bio-media I have picked up from retired aquarists and used filters because over time they become brittle and messy, bleaching only seems to hasten this deterioration. On the other hand, I am still using most of the ceramics I purchased in the 1970s; it remains my favorite bio-media for canisters and reactors making it possible for me to reliably hold more inches of fish-per-gallon than would otherwise be prudent.