Sexist Irony...or Ironic Sexism, if you prefer
So, I found the scene with Mrs. Judith Loftus to be particularily interesting. When she figures out that Huck's a boy, and rattles off the list of details that made it obvious, I was momentarily reminded of spy novels I've read (far too frequently). The hero always picks up on some subtle detail to pick the assasin out of the crowd, and Mrs. Loftus seemed to do that to Huck. (Though there wasn't a crowd, and she was intent on helping him rather than sneaking up behind him to silently slit his throat).
Anyway, it was interesting because she gives him several sexist stereotypes to follow in order to better fake being a girl. Ironic, because at the same time she tells him his current act is so bad that only a man would fall for it. Through this section Clemens is able to effectively satirize a whole lot of stereotypes. While he may be saying that girls suck at throwing, the main point is that they're smart, and perceptive. The level of detail that Mrs. Loftus picks up on is really quite impressive (Especially for a woman (just kidding)).
Though his satire tends to have a pretty specific target, (in this case slavery), Clemens is ALWAYS ready to take a few subtle shots at any worthy targets that linger in his crosshairs. That is just want makes him so much fun to read.