Can you remember where you found that sponge cleaning video?
May need it soon.
I think I searched (using DDG) for “Clean Canon Ink Absorber”. There are several out there for different types of Canon printers - the process for mine is quite simple (use tweezers to remove the pads, squeeze them out in warm soapy water, dry with paper towels and reinstall). The problem is that there is a counter that has counted prints and has hit its limit - so the printer doesn’t actually know if the pads are saturated. So you have to reset to clear the counter. Sounds like planned obsolescence to me (though the printer is several years old and has printed a lot of stuff).