After looking though a number of recipes, including several on French sites and one titled as "real," it doesn't look like it requires anything special. Certainly not the easiest dough to handle and some fine touch needed to keep the butter from breaking through, but nothing technically elaborate. I guess I'll try it. Apparently it's harder than it sounds, which is a worthy challenge. I'll have to fake the Breton butter. I keep European style high butterfat butter and some about half course sea salt. Won't be exactly the same richness as Breton country butter, but it should work. But mainly, it sounds like you have to work quickly. And probably not be discouraged easily.
"Kitchen duty is awarded only to those of manifest excellence..." - The Master, Dogen