Praise be to Allah.
Firstly:
The majority of scholars are of the view that wiping the ears when doing wudoo’ is Sunnah and mustahabb (encouraged), and not obligatory. The Hanbalis and some of the Maalikis are of the view that it is obligatory.
See: al-Mawsoo‘ah al-Fiqhiyyah (43/364-365).
The scholars of the Permanent Committee for Ifta’ favour the view that it is obligatory.
See: Fataawa al-Lajnah ad-Daa’imah (4/88).
Secondly:
With regard to how they are to be wiped, the insides of the ears should be wiped with the forefingers, and the outsides with the thumbs. It is not required to follow the cartilage of the ears when wiping.
At-Tirmidhi (36) and an-Nasaa’i (102) narrated that Ibn ‘Abbaas (may Allah be pleased with him) said: The Messenger of Allah (blessings and peace of Allah be upon him) did wudoo’, then he wiped his head and ears, wiping the insides with his forefingers and the outsides with his thumbs. Classed as saheeh by al-Albaani in Saheeh an-Nisaa’i.
An-Nawawi (may Allah have mercy on him) said in al-Majmoo‘ (1/443):
The Sunnah is to wipe the insides and outsides (of the ears). The outside is that which is next to the head and the inside is that which is next to the face, as was stated by as-Saymari and others, and this is clear. With regard to how this wiping is to be done, Imam al-Haramayn, al-Ghazaali and others said: He should put his forefingers into his ear canals and rotate them, running them over the area around the ear canal, and pass his thumbs over the outsides of the ears. End quote.
It says in al-Mawsoo‘ah al-Fiqhiyyah (43/366):
The Sunnah when wiping [the ears] is to put the forefingers into the ear canals and wipe the outsides with the thumbs … It is not required to wipe the part of the ears where there is gristle [cartilage]. End quote.
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said:
The way to wipe the ears: the forefingers, meaning the fingers between the middle fingers and thumbs, should be placed in the ear canal, without pushing so much that it causes pain, whilst using the thumbs to wipe the outside of the ears, which is the surface that is next to the head. End quote.
https://binothaimeen.net/content/11897
We do not know of any saheeh hadith about the manner of wiping the ears which says that it should be done with the pinky and ring finger. What is prescribed is to wipe them in the manner described above, which is proven in the hadith of Ibn ‘Abbaas (may Allah be pleased with him). But if the inside and outside of the ear are wiped with whichever fingers one chooses, that is good enough, although the Sunnah, as noted above, is to wipe the outsides with the thumbs and the insides with the forefingers.
With regard to the questioner saying that he read a fatwa about using the pinky finger to wipe the ears, perhaps he meant the forefinger.
And Allah knows best.