It's clearly been done before, as he followed the instructions from a book. Clearly he didn't just invent it. Sorry that this show might be too complex for your little mind.

Oh, God. You're back again with this shit?

Didn't you get embarrassed trying to flex your GoT knowledge on us peasants?

This. Sam even had a conversation with the Grand Maester about it.

I've read the series twice. You know shit about GoT.
Don't make me be the next guy to bang your girlfriend stick man.

Frankie lives again.

You've read it twice, and still can't pick up simple clues?

Come on you cockless coward.

Nah I'm not Theon.

I've read the series as well. Could you clarify where in the book it said anything about the cure for Grey Scale? Not being facetious, just curious.

If I recall, Stannis called for someone/anyone, including priests from across the Narrow Sea; I just don't recall anything being definitive.

You are correct on both counts.
There was never a mention for cure. And yes Stannis called for the mining of dragon glass on Dragonstone after he learned of it's properties when he went to the wall. Nothing has come of that yet though.

:D That's a good thing.

I guess where I'm headed is that the show has surpassed the books; just because you don't like the presentation of the story doesn't make it less valid.

Also, judging by the welcoming party Dany received, I think that command has been resciended :D

I think the Maesters in the Citadel, and particularly the Grand Maester, are a bunch of curmudgeonly old bastards that couldn't care less about Greyscale or curing it, even on a knight. Once Sam learned Jorah was a Moromont, there was no way he WASN'T going to give it a shot.

And IIRC, he stumbled upon the cure while researching how to weaponize dragonglass against the White Walkers.....

I also, from reading the books, got a sense that the maesters carried themselves in high esteem. They kind of seemed to be know it alls, and looked down on the kingdoms. Not sure if anyone else got that sense.