As an addendum to this question I think the relevant point here is; does bleach stop bleaching things after it has dried?
This is a really simple one. Bleach is bleach regardless of whether it has dried – have you ever bought those solid bleach tablet things that you’re meant to drop in the toilet? They’re dried, concentrated bleach and they still do the same job. So when you use the normal stuff and it dries, you’re left with an invisible layer of dried bleach on the surface. When you use lots, or put it down the loo, it evaporates into the air the same as any other liquid does. Except that it is then bleach dust, milling about in the air, free to settle on all the nearby surfaces just like all dust does.
So you’ve got a house with invisible bleach on many of the surfaces. What happens then? What does it do?
If it settles on clothing, then often when that clothing goes through the washing machine it will fade a little. You will usually only notice this after many washes unless it is a particularly delicate fabric. That’s why clothes start to look old and dull after they have been washed a lot.
But the most important thing bleach does is settle on things that you touch. Slowly but surely you walk on bleached floors, touch bleached taps and handles and surfaces, and each time the bleach wears away a little tiny imperceptible shade of your skin pigment. The contrast will obviously be more vivid the darker your natural skin pigment.
This is why it is impossible to get a tan on the palms of your hands or the soles of your feet.