I found my "Buddho", on singular hill

I use to think Ajahn Mun and his disciples teaching “Buddho” mantra was a very questionable practice, not in accordance with EBT. It also bore some disturbing similarities to Pure Land Buddhism, if one becomes attached to a mantra without understanding what it’s used for and why. In the EBT at least, it turns out Ajahn Mun is justified. You can use a “Buddho” mantra as an entry into samadhi, following the 7sb formula, if you do it this way.

AN 6.10 6 recollections (buddha, dhamma, sangha…) leads to samadhi and Dhamma stream entry

AN 6, 1. paṭhamapaṇṇāsakaṃ, 1. āhuneyyavaggo, 10. mahānāmasuttaṃ (AN 6.10), para. 2 ⇒
“yo so, mahānāma, ariyasāvako āgataphalo viññātasāsano, so iminā vihārena bahulaṃ viharati. idha, mahānāma, ariyasāvako tathāgataṃ anussarati — ‘itipi so bhagavā arahaṃ sammāsambuddho vijjācaraṇasampanno sugato lokavidū anuttaro purisadammasārathi satthā devamanussānaṃ buddho bhagavā’ti. yasmiṃ, mahānāma, samaye ariyasāvako tathāgataṃ anussarati nevassa tasmiṃ samaye rāgapariyuṭṭhitaṃ cittaṃ hoti, na dosapariyuṭṭhitaṃ cittaṃ hoti, na mohapariyuṭṭhitaṃ cittaṃ hoti; ujugatamevassa tasmiṃ samaye cittaṃ hoti tathāgataṃ ārabbha. ujugatacitto kho pana, mahānāma, ariyasāvako labhati atthavedaṃ, labhati dhammavedaṃ, labhati dhammūpasaṃhitaṃ pāmojjaṃ. pamuditassa pīti jāyati, pītimanassa kāyo passambhati, passaddhakāyo sukhaṃ vediyati, sukhino cittaṃ samādhiyati. ayaṃ vuccati, mahānāma — ‘ariyasāvako visamagatāya pajāya samappatto viharati, sabyāpajjāya pajāya abyāpajjo viharati, dhammasotaṃ samāpanno buddhānussatiṃ bhāveti”’.
“Mahānāma, when a noble disciple has reached the fruit and understood the instructions they frequently practice this kind of meditation. Firstly, a noble disciple recollects the Realized One: ‘That Blessed One is perfected, a fully awakened Buddha, accomplished in knowledge and conduct, holy, knower of the world, supreme guide for those who wish to train, teacher of gods and humans, awakened, blessed.’ When a noble disciple recollects the Realized One their mind is not full of greed, hate, and delusion. At that time their mind is unswerving, based on the Realized One. A noble disciple whose mind is unswerving finds joy in the meaning and the teaching, and finds joy connected with the teaching. When they’re joyful, rapture springs up. When the mind is full of rapture, the body becomes tranquil. When the body is tranquil, they feel bliss. And when they’re blissful, the mind becomes immersed in samādhi. This is called a noble disciple who lives in balance among people who are unbalanced, and lives untroubled among people who are troubled. They’ve entered the stream of the teaching and develop the recollection of the Buddha.

Also baked in as "saddha" in 5ind and 5bal formulas

SN 48.9 paṭhama-vibhaṅga-suttaṃ

SN 48.9 paṭhama-vibhaṅga-suttaṃ
SN 48.9 first-analysis-discourse
“pañc'-imāni, bhikkhave, indriyāni.
"(There are) five-(of)-these, *********, faculties.
katamāni pañca?
Which five?

(1. Saddha: Conviction)

katamañ-ca, bhikkhave, saddh-indriyaṃ?
{And}-what, monks, (is the) conviction-faculty?
idha, bhikkhave, ariya-sāvako
Here, monks, (a) disciple-of-the-noble-ones
saddho hoti,
{has} conviction,
saddahati tathāgatassa bodhiṃ —
convinced (of) the-Tathāgatha's awakening -
‘iti-pi so bhagavā
'Thus-indeed, he, the-Blessed-one,
arahaṃ sammā-sambuddho
(an) Arahant, properly-awakened,
su-gato loka-vidū
well-gone, world-knower,
an-uttaro purisa-damma-sārathi
un-surpassed man-training-leader,
satthā deva-manussānaṃ
teacher (of) devas-(and)-humans,
buddho bhagavā’ti —
(the) awakened-one, the-blessed-one -
idaṃ vuccati, bhikkhave, saddh-indriyaṃ.
this (is) called, *********, conviction-faculty.

These qualities (or names) of the Buddha should be recited while remembering the meaning of each, rather than as a mantra- as Frank has mentioned above. I doubt that the Buddha would have a problem with counting as an aide to keeping ones mind on the breath either. Buddho (ideally) should not be used in a superstitious, and therefore like as ‘rites or rituals’ (silabbataparamasa) manner. Recollection of th Buddha’s virtues are done widely as a practice in Aisan countries, and I believe is one of the 4 ‘preparatory’ meditations (caturarakka bhavana) that help manage the hindrances -this categorisation is late, while the meditations aren’t, faith not playing the same role as in western religions.

with metta