I've heard the whole "new wine = grape juice = what Jesus really used" argument. It doesn't wash, for a couple of reasons:
a) Wedding at Cana - the steward comments on the quality of the wine. Now there is an appreciable difference in the quality of different wines, but not of different grape juices. Ancient Israel was not like today where we have all sorts of chemical flavourings, colourings, preservatives and so on that affect the quality of a fruit juice, it would've all been good!
Nor would people serve inferior grape juice last at a celebration because after drinking good grape juice that they couldn't tell the difference later. It doesn't compute unless it's actual alcohol he's referring to.
b) Jesus was accused of being a glutton AND a drunkard - impossible if He stuck to grape juice.
c) Passover has often been discussed. 'Nuff said already.
d) The Apostles on Passover start speaking in a manner that is unintelligible to those listening, who sneer 'they must have been drinking new wine'. In other words the argument is 'they are drunk', as grape juice doesn't cause strange speech!
Not only that, Peter gets mortally offended at the suggestion and reminds his listeners that it is still only early morning. Why would anyone get offended at the suggestion that he had been drinking grape juice?
I love the 'they are the same thing' comment. Jesus didn't say 'do near enough to what I've done', He said 'do THIS' - in other words the same thing. If grape juice is the same thing as wine then attempting to observe the 'Lord's Day' on a Wednesday is exactly the same as truly observing it on a Sunday. :shrug: