I don't hate you and I appreciate you

Thank you for your question, lost person.

“I don't hate you. I'm grateful to you.” The monk who explains that purpose is probably someone from the Hokke Sutra family? I'm guessing.

If so, aren't they trying to talk about Jofukaru Bosatsu (Jofukaru Bosatsu) in the Lotus Sutra?
Joshukaru Bosatsu prays with the same hands (yes) with each person he meets and says, “I respect you. We will never take it lightly. This is because you are the one who acts as a Bodhisattva and can become a Buddha,” she said aloud and prayed.
The sutras are “I deeply respect you, you dare to despise yourself, what are you, the one who dares to be compassionate (who) dares to be condescended (so) is what (iika) do you all do in the way of the Bodhisattva to obtain Buddha (masa) making (masa)).
He was called Jofukyo (Jofukyo) Bosatsu because he doesn't always disdain people, and it seems that the person who was told was surprised, thought he was made a fool of, and threw curse stones at Tsunefukaru Bosatsu, but it seems that Tsunefukaru Bosatsu stayed away from that harm, did not get angry, and continued praying while chanting the above words. And it means that Joshukaru Bosatsu gained a clean heart, became a Buddha, preached the Lotus Sutra widely, and made many people attain Buddhism, including those who caused harm.
It is explained that this is Buddha's own past Bodhisattva act.
It has nothing to do with chanting three times, irritating content, or hypnosis. It is an act of faith that Buddha will always be attained through the act of the Bodhisattva in the Lotus Sutra.
When you worship anyone, it means that people with Buddha nature are praying for each other. Since Buddhism worships Buddha sex, it is a pure act of faith where if you are aware of it, you will understand each other as the Buddha appeared.

That's for reference only. Gassho prayer

I read your question.
I don't know what context or intention the monk mentioned was written in, so I can't determine if it's a self-hypnosis method, but I think it's one of the ways to “forgive.”
The world does not revolve around us, but there are more than a few cases where we try to pass ourselves through it. If you do that, of course, friction with people around you will occur, and sometimes you will feel a grudge against your partner. But it's like poison, and it eats away at our hearts. When we are being devoured by poison, no matter what we do, we cannot truly enjoy or taste it. Such poisons are purified by “forgiving.”
I listened to the monk's words, and it appears in the “Shodo Song,” which is a classic of Zen Buddhism, “If you see bad words as merit, then this in turn becomes good knowledge (there are people who speak ill of themselves or deal harshly with themselves, but thanks to such people, I grow and refine myself. (The person who speaks ill of me is my teacher.)” I was reminded of that passage, and I think this is also a kind of forgiveness.
In fact, when you're feeling tough, it may be difficult to think like that, but whether your partner is malicious or well-intentioned, there are more than a few things that feed for yourself if you think about it later.
I think these things are understood by gaining insight into the inner world of the self rather than logic or mechanism.