Haha…I once lived in a monastery in a Japan for a month, right outside Kyoto. There was an Australian tourist who was visiting and he kept pestering the head monk there for a mantra. The monk tried telling him, “No, watch your breath, thats what we do” and eventually got tired and told him, “observe your mind reciting this mantra - kukola kukola”… That did help the tourist as he did it mindfully and within a few days, experienced bliss. Essentially, instead of the breath, he was focusing on this phrase.
And then the head monk one day told me, “See, you Vajrayana guys spend years reciting mantras, kukola does the same”. I did not say anything… A few days later, it was new moon, and I invited him to a ritual I was doing for Kali and he reluctantly agreed. And when the energies of the Goddess arrived, with a big bang like she always does, he was awestruck, petrified, scared out of his wits - all at the same time and his strongly held worldview was fully shattered.
He later decided to study under Rinpoche Namkhai Norbu and never ever made fun of mantras or Vajrayana again haha… He still lives in Italy in some city outside Naples.