Some people will embrace (or pretend to embrace) any absurdity before conceding a point in a discussion/debate. For example, let's say you run into somebody who says all knowledge comes by way of our five senses, and you can't know anything apart from your five senses, yet there's quite a lot we can know about the external world. You respond by saying the only way our senses could tell us anything about the external world is if we already knew our senses were giving us true information about the world. After all, it's at least possible that we're plugged into the matrix. To press the point a bit farther, you say that their epistemology leads to solipsism when taken to its logical conclusion since you'd then be stuck inside your head with no epistemological way to make a connection between your perceptions and whatever external reality might exist outside your head. Rather than concede the point, or even qualify their epistemology, the person you're talking to will say, "Okay. Solipsism it is." Yes, I have actually had this very conversation with somebody, and that is what they did.
A long long time ago, I used to argue with people like that. I would argue with them with the goal of convincing them they were wrong. I would take any absurdity they threw at me as if it were a serious argument, and I'd try to respond to it. I'd basically run the argument into the ground. I wasn't really trying to embarrass the other person. I was trying to get my point across because I took them seriously.
Then I read J. Budziszewski's book, How To Stay Christian In College. There was a section in there about what to do when somebody throws up a smoke screen--something you suspect the person doesn't really believe. The example he used was of a moral relativist who, when asked about murder, says, "How do we even know murder is wrong?" Budziszewski suggested that instead of arguing with the person about whether murder is wrong, say something like, "Are you in any real doubt that murder is wrong?" I started using this technique in a lot of discussions, tayloring it to the occasion. I would say that about half the time, it works. The person will come clean and admit they aren't seriously entertaining solipsism, that murder is okay, or whatever the case may be. The other half of the time, I either try harder to get the person to come clean, or I press the argument and go back and forth with them.
A few years ago, I started doing something different, though. You see, sometimes people will dig in their heels in order to save face. They will defend any absurd notion rather than admit to being wrong. Reductio ad absurdum doesn't work with these people because they'll embrace the absurdity rather than concede the point. So what I started doing is once I've made my point, and once the other person has started to dig their heels in defending something that's absurd, I'll drop the subject. I'll let them get the last word. This is the way I look at it. If you push somebody into a corner, causing them to dig in their heels, they'll just get more entrenched in their point of view. They'll convince themselves of the absurdity, and they'll be even more comfortable defending that absurdity later on. But if I allow them to save face, then they'll be able to go off by themselves when the pressure is off and think about it without any fear of embarrassment. I figure people sometimes say things they don't believe in order to save face. So if I resist the urge to argue with them, they'll be able to see the force of my argument. It shouldn't matter to me whether I got them to admit it or not as long as I got my point across. So once I think I've gotten my point across, I'll drop it. I won't argue with them anymore.
I don't know whether it's working or not, but I can tell you it has saved me a lot of frustration. Going back and forth with people--especially people you suspect are just pretending--can be exhausting. Sometimes it's hard to let an argument go and not respond, but I'm a much happier person since I started doing that. Plus, it frees me up to enter new conversations without being bogged down in the old ones.
You might wonder about the audience, though. If you're arguing with somebody on a public forum with other people watching, you might feel the need to continue arguing for their sake. I don't worry about the audience, though. They're not in the position of having to save face, so there's no worry that they're going to dig in their heels. You have to just give people some credit and let them judge for themselves whether or not the other person is just being silly. Trust them to see the force of your argument. You don't have to run it into the ground.
