If there's no extant disclosure of the means to work the invention then I don't see why not. For example we could find that you got the method wrong, and thus that no prior art existed. If there's a document, stele, or something you can examine to learn how to work the invention then that would be prior art.

Recall, USA have harmonised with the other systems now on using "first to file".

However you'd have to be the inventor, so you'd need to be able to argue you'd reinvented it. In practice you could just not reveal your source and probably get away with saying you invented it.