There's loads of good info here on BoB about re-hydrating dry baccy.
One technique I've used successfully is this-
Put the toby in a bowl and spread it out to a more or less uniform thickness.
Get a plain white washcloth or towel (gotta be white), moisten with distilled H2O (like from a spritzer bottle), do not oversaturate!
Place over bowl, making sure the cloth does not touch the toby.
Leave for say 4-8 hrs. Take off cloth and check for moistness. Repeat as necessary.
This has worked really well for me on the rare occasions I've had to rehydrate crispy baccy. Of course the question is always "what would it have been like before it lost all it's moisture and aroma constituents"?
Can't answer that. Only can tell you this technique works for me.
HTH
:sunny:
Cheers,
RR