You speak my language... I managed to wipe out Orthodoxy that way and, in the end, Protestants and Reformed didn't have more than five provicnes combined.
It was also a politically good move: it allowed me to Balkanize entire Europe so that only me and Britain mattered
Orthodox? What is this "Orthodox" you speak of?
Okay I haven't done nearly as well as you - there are two Orthodox countries left and three other Orthodox provinces that haven't been converted yet - I'll have to look into crushing Montenegro and Trebizond soon. I also had a particularly rough Reformation - almost every country in the Holy Roman Empire except Bavaria, Brandenburg, Pommerania, and my own Teutonic Order flipped to Protestant or even Reformed. Aachen embraced Heresy twice (Charlemagne would be rolling in his grave), once I reverted them, the other time Bavaria enforced religious unity. I personally forced Bohemia, Switzerland, Burgundy, Utrecht/Holland, Gelre, Munster, The Palatinate, Cologne, Trier, Frankfurt, Mainz, Saxe-Lauenberg, Mecklenburg, Breda, Anhalt, Wurzburg, Liege, and Meissen to flip back, and probably at least one other minor I forgot. Liege obviously turned away from the face of God, again, to my chagrin, so they shall receive neither Holy Communion nor Mercy from me. Thuringia and Silesia are my vassals so I haven't ended their vassalization and forced them to recant although I think I'll have to. I held off on hurting The Hansa because until they recently flipped to an Administrative Republic I was in their trade league with two dozen trade stations giving me various nice things. Outside the HRE I forced England, Poland, Ukraine, and Lithuania to recant, as well as the aforementioned war with Sweden that reduced my +55k stockpile of bodies to less than 8k.
As you can see, getting rid of The Taint entirely is going to be a difficult job. I imagine I'll need at least 110 regiments (and my quality slider is almost maxed out) to tackle Austria on its own.