I've tried "reading aloud" my own "lost chapter" from AHF (on my web page)
and in front of a creative writing class. It's remarkable how something
that seems so killingly funny in writing (to me at least) can flop like a
pancake when read aloud.
Twain mentions this problem in his autobiography regarding the story of the
ram and shows how something that people might find funny in print is not
necessarily funny when read aloud. This of often why stand-up comics are
seldom funny in their written "comedy." (Al Franken comes to mind.) The
transition from spoken to written, or from written to spoken, is not easy,
for each mode of humor has its own special tricks and techniques that cannot
be easily translated into a different mode.
When reading aloud, I don't see that there's any other way than the way
stand-up comics do it: you have to practice in front of a dog, so to speak.
Kids might laugh at the way a word is spoken, even if wasn't meant to be
funny in the text. Or, they might give a blank stare over a text that
produces a (real) laughing revival in anyone else. One can only find out
what works through experience in front of an audience.
It would be interesting to hear a "read aloud" version of Huck and to see
whether it produces more laughs than Twain's written version. And I don't
see any problems reprinting a read-aloud version on your web page, since I
think the statute of limitations has run out on Twain's works. But if it
involves perhaps some special editing provided by Blair, you probably can't
print that; it would have to be some kind of an original work of Twain.
However, if it's your own stuff, there's no copyright problem.