Audacity is alright for the task to be fair. I have used it with carying results removing guitar solos. Centre cancelling is hit or miss whatever you do, due to the number of instruments that get mixed to the middle. When you consider most people will mix bass, kick, vocals and others straight up the middle, taking out the vocals can hit other instruments. That's why the results sound so weird. It can be achieved in studio one and Joe Gilder has a video about it wither on Home Studio Corner or the Presonus channel. I will find it if I can and post it here. Basic theory is phase cancellation and sample offset. Please bare with me as I find the video. I watched it months ago.
