you can bend/compress wood with steam. But look at the width of that bottle neck.
The others I looked at (playing cards, rubicks cube, ...) can be disassembled in smaller pieces that go through. That's his technique. So how do you disassemble a plank? I think it's a hollow piece of thin plywood (1 piece, no seams) that was soaked, folded up and then filled with something (resin).
This is actually a pretty common misconception amongst muggles. A magician's trade is to lie with action, not with words, and most magicians I know have a very strong sense of honor in this regard.
Magicians do not often reveal their secrets, and I suppose some would even lie outright if you try to out them in public (although a good magician would find a way to ask you to stop ruining everyone's fun), but when a magician voluntarily tells you how something was not done, you can usually trust him. That's doubly true for respected magicians. I think it's a big part of what makes them respected.
Also, in the case of the bottles, cutting the bottom would not only be extremely easy to detect, it would also make the whole thing worthless. A cheap scam. Magician's consider themselves artists, not scammers.
> So the bottom was cut open and sealed by heat then.
Even if that's true (which it's not, according to the creator), there's no call to be so dismissive and superior about it. Seamlessly cutting and resealing a bottle is sure as hell not in my skillset, and I'd be pretty impressed by someone who could do it reliably.
I would love to know why my comment was down voted. I'm making a fair point that nobody else has yet made, and thus I would argue that it adds value to the conversation. Sure, my comment was short but I believe it was as long as it needed to be to make the point. To clarify though, in case I was wrong on that assumption, I'm stating that simply because one can't spot any breaks doesn't mean there aren't any. Maybe Eng did a really good job of splitting the wood along the grain and piecing the wood back together once he slipped each piece inside the bottle. And then he could have finished the wood in such a manner as to hide any cracks still visible.
I'd prefer to try to riddle it out without resorting to cutting the bottle open. That would take all the fun out of it. If you had a reliable way to cut bottles and reassemble them with no telltale marks, then a single trick would explain all the different bottles. Much less interesting than if each bottle required a unique, clever solution.
Ignoring the wood for a moment, I'm focused on the padlock. Suppose it's not a real padlock. There are stripes on it which, to my eye, look like they might be corrugation. Perhaps it's hollow and can collapse like an accordion.
Edit: Or, per the description of the second-to-last bottle, the lock is broken down into parts and reassembled in the bottle.
Now, if you were to delaminate the lock's layers and reassemble it piece by piece inside the bottle with authentic-enough looking rivets, I can see it fitting through the neck without a problem, but I don't have an explanation for the solid piece of wood that large.
The padlock seems like the least of your worries. How the hell did the plank get in there? The only thing I can think of is the plank was split and glued back together once inside.
I think the padlock would fit if you took the shank off.
Some woods (including pine) are much more compressible than you might expect: http://www.ewpa.com/Archive/2006/aug/Paper_306.pdf