I'm not saying that wp-blacklist is junk, nor would anyone else, I think. However, if it doesn't seem to be working for you, then move on to something else. There's lots of choices out there. While I happily promote Spaminator, it may not be for everyone. I like it because it gets everything in my comment spam list and I turned off the "send me an email when spam is killed" and my inbox is happily devoid of stuff. Once in a while a new spam makes it past, only to be caught by another of MooKitty's spam tools, and I moderate it, adding the info with one click to my comment spam words list, and that's it.
So, like I said, if it's not working, it's not necessarily a bad plugin. It's just not doing what you want, and , perhaps, a combination of other plugins and your site design could interact in a negative way. It's happened before that some plugins step on the toes of other plugins.