Who said anything about half-hard? I think the post meant half-way.
Oh, by the way, in case you're feeling like everyone out there who's any good in bed does this... even Jenna Jameson said in an interview she's only done anal a few times, with 3 guys (not at the same time), and she was in love and in a relationship with them at the time. Not even porn stars are comfortable or experienced with doing everything I guess.