ἐκνήφειν ἀπὸ τοῦ οἴνου is used in literal sense of "coming to" after drinking, e.g. Noah realising what had been going on while he had been blacked out with the wine (Genesis 9:24). In the story of David, Abigail and Nabal in 1Kings (Samuel) 25:37, Nabal was supposedly in no fit state to be taking in any news, till the morning. Presumably then in a figurative sense, ἐκνήφειν means coming to the stark realisation of just what we had done in our state of drunkenness, or what had been going on around us.1 Corinthians 15:34 wrote:Ἐκνήψατε δικαίως καὶ μὴ ἁμαρτάνετε·
Whether that is more-or-less to the point or close to it with regard to the literal use of the word ἐκνήφειν, my biggest difficulty comes with an adverb of manner (δικαίως), seemingly used with the idea of purpose.