Buddha occult charms

[Lightseeker]

In the Kevatta Sutta, Buddha is explaining to Kevatta why he doesn't use miraculous powers for his teaching. And while telling about psychic power he tells:

Then the person without faith, without conviction, would say to the person with faith and with conviction: 'Sir, there is a charm called the Gandhari charm by which the monk wielded manifold psychic powers...exercising influence with his body even as far as the Brahma worlds.'

And while telling about telepathic power Buddha says:

"Then the person without faith, without conviction, would say to the person with faith and with conviction: 'Sir, there is a charm called the Manika charm by which the monk read the minds...of other beings...' What do you think, Kevatta -- isn't that what the man without faith, without conviction, would say to the man with faith and with conviction?" "Yes, venerable sir, that's just what he would say."

So it seems that it is possible to gain psychic power through Gandhari charm and mind reading power through Manika charm. I want to know what these charms are.Are they Mantras? Do any Buddhist scriptures describe it? I'm well aware that Buddhist scripture do not focus in attaining these powers and Buddhism is related with ending of suffering.

But as those charm names are spoken by Buddha himself, maybe it's possible to get knowledge about those charms. Also if there is some ancient commentaries of Kevatta Sutta, then maybe some information is avaliable there.