I will set aside my concerns over the use of the expression "outrageously talented", only saying that hyperbole can be problematic.

I am not unfamiliar with various approaches to the singing and teaching of chant (having attended workshops with Fr. Columba Kelly, OSB at St. Meinrad, for example) and have also attended a workshop given by Mr. Sarweh several years ago, and I think it is excellent for one interested in exploring some of the more detailed and esoteric aspects of chant (application of the modes, historical interpretation of rhythm, use of isons and other effects), especially if one already has a strong background and experience in the singing of chant (including the interpretation of St. Gall and Laon neums). However, if one is seeking an opportunity to learn the basics of chant that can then be taken to, and applied in, a parish schola environment, this is perhaps not going to be of great benefit.

Mr. Sarweh's approach seems to be more rooted in the "Old Roman" style. He advocates the use of isons and other approaches to the singing of the chants, including an improvisatory style applied to the Propers that requires a solo voice familiar with and trained in the "Old Roman" style rather than a more conventional (i.e., semiological or "strict Solesmes") approach to interpretation of the more complex neumatic groupings commonly found in the Proper chants. Much of what he teaches is applied to the singing of the Ordinary and to Latin hymns.

There are a few examples of his work found on YouTube (including the "Alleluia", below, and several versions of the "Kyrie" Orbis factor; search under his name), and these will demonstrate to some extent the kinds of approaches to chant he employs in his own work.

As always, YMMV. I have no desire to get into a debate about the merits of Mr. Sarweh's approaches. I merely wish to present more information regarding his work.

https://www.youtube.com/watch?v=7aT3yBLhGYk