a method of housebreaking pets

To housebreak or housetrain a (usually young) pet means to train the animal not to pee or poop in the house, or perhaps with a cat, to use a litter tray. A pet which has been successfully trained in this way is said to be housebroken. We often use 'break' in expressions about training animals, for example to 'break in' a horse means to get it accustomed to being ridden and obey the directions of the rider.

Thank you very much for your help.

Would you please explain how "rub the nose in it" is originally related to the method of pet training?

Does it refer to owners of pets would rub the nose of pets, if the pets don't behave desirably as you illustrated? Do pets feel uncomfortable if people rub their noses?

Rub the nose IN the poop or pee.

From your post:

If the pet poops or pees in the house, the owner grabs the animal's head and forces the animal's nose into the poop or pee and rubs the nose in the offending matter. The idea is to teach it to go outside or in its special place. Some experts think it is a bad method.

Note:

Rub can be transitive or intransitive

Intransitive: describes motion by a person's body or a part of it (often a hand), or a thing, against something or someone else. My cat rubbed my leg as it walked past. My shoe has rubbed my foot and made it sore. I rubbed my dog's head when he came to me.

Transitive: describes making something move against something or someone. I rubbed the window with a cloth. I rubbed my fingers together. He rubbed the stain with a wet cloth. Some people rub pet's noses in their faeces to stop them defecating in the house.

Resolve ambiguity: Some people rub the nose of a pet in its own faeces to stop it defecating in the house.

I see now. It's very kind of you to help me out time and again.

Cen, what a....fella yo !! Oft addressed this very q; thanks for that; f'tunately Nelson's pops are dry, easily picked up for use outsiee. Oft wonder whether they're good compost.

The way to teach a kitten where to pee/poop:

When you first bring the kitten in the house, the very first place you place them down is the litter box. If you keep the litter box in the bathroom, then explain while doing your business.

Then take your kitten on a tour of your house; walk them over to the food dish, explain out loud this is where we eat, and prepare a meal for them.

Thank you for your reply. Sorry I didn't make myself clear. I am not a native speaker of English. I post this thread to ask the meaning of "a method of housebreaking pet" in English, and the relevant idiom - 'rub the nose in it'.
In short, it is about language, but not pet training.

Yes.

But Cen, nothing is entirely anything, while everything is partly something else