I only had one person on Ignore at TXB, too, who shall remain nameless. He's the only person I ever used it on. I only used it for a week or two, then ended up taking him off Ignore. The way TXB handled it, by posting that little line, "This message is hidden because you have X on ignore" actually made it stand out more and drew my attention to the fact that he had posted. And the fact that I couldn't read it -- that just piqued my curiosity, so sometimes I'd "peek" at what he'd written. I realized this was a pointless waste of energy, so I took him off Ignore.
Now that I'm a mod, I can't have anyone on Ignore. I still "manually" ignore people, though -- just scroll past what they say, that is. There are certain people, where I know that 90% of what they say is drivel, so it's just not worth bothering to read.