CoS questions - Nick's unpetrification

[amanitamuscaria1]

No: HPFGUIDX 95487

I'm re-reading CoS (yet again), and was trying to work out how N-H-
Nick got unpetrified. At the Deathday party, we learn that ghosts can 
only 'almost' taste food as they walk through it, so how would the 
mandrake root potion be administered to him?
I had a search through past history, but couldn't find anything 
relevant in 10k posts (geez - it's nearly 100k posts here!)
Anyone got any ideas?
I'm veering to Dumbledore doing something, but then think if he could 
revive Nick, he could probably revive the others, and then, why 
wouldn't he? At that point, I get into Dark!Dumbledore, and way too 
confused!
Cheers. AmanitaMuscaria