Sorry, LH, the "S" item on the list is "solar heating". Not nearly as provocative as smegma, I know. But, remember that the list is limited to things about which we've never chit-chatted here on the MOAB. With this crowd the chances of smegma not having been discussed somewhere in its 1700+ post history are pretty slim. (Sorry, but I'm not going to reread the entire thing to make certain.)
Anyway, even if we've never discussed smegma previously, now we have discussed it so it is disqualified.

Wasn't "Smegma" the name of the Gollum character in Harvard Lampoon's LOTR parody Bored of the Rings?