Never tried that, but I don't belive it'll work. You can, however get USB diplexor that will do what your looking for. Problem, they tend to look gawdy. It's just a little gray box, usually with an (A,B,C,D) switch on the front, but for a few buck more I'm sure you can get an automatic version. I don't know where they're sold, but
pricewatch is always a good starting point. Never personally Had a USB Diplexor, but I used to have a bunch of Parallel Diplexors. Keyword(s)- Used to.

<Orwell> WTF are they doing upstairs. Almost sounds like construction
<[Kristyrat]> Orwell, you see / <[Kristyrat]> when a man really likes a woman / <[Kristyrat]> or has a bottle of chloroform
<inthesto> He takes her stuff / <inthesto> And then poops in her vagina