I know you didn’t ask me the question, but in my experience it is rare that an elderly person has no way to remove the blocks. They usually have kids that visit frequently or a cleaning lady that comes once a month that can remove the blocks.
If they really have nobody to help them, we won’t wet under the item that would otherwise need blocks. Almost always there is a compromise the customer understands and agrees to.
When I started out I was tabbing and blocking everything. Then the next visit they would still be there on some jobs so I adjusted how I approached it.
Antique and real wood furniture got tabbed or cleaned around due to the staining issue. Some chairs have metal sliders under them that can rust too.
I could sometimes tell when they used a different cleaner from the blocks or tabs I would find.
I try and not put everything back in place on some jobs and tell the customers to wait until its dry before moving it back to prevent that spot from staying wet too long.sometimes when tabbing they remove it and it can still be wet defeating the purpose.
Its all solved by talking to the customer and explaining your concerns.
If they want cat odors removed and my light shows pee on the wall I have to treat the wall and baseboards too. I just show them the light so they understand what im doing.
And I dont video in peoples homes. I find its not professional. Im there to clean not to make a commercial. Too many carpet cleaners trying to be youtube stars.
I usually dont even carry my phone when im working.