You mean US English. Sure, I know what "doo doo" means from US TV/movies, but I've never heard anyone use it. Neither would I assume poo if someone said it in relation to Linux.
That's because the word is generally considered juvenile - something a child of 2-12 would probably find hilarious. And despite how you might tell them to pronounce it, I'm pretty sure they'd end up calling it "doodoo" anyway, at least mine would.