In Russian we have an idiom “Zub dash?” or “Zub dam!”, which means roughly: “will you bet your tooth on this?” and “I’ll bet my tooth on this!”, correspondingly (both ways, it’s not exactly posh). We usually ask the first question, when we want to know if our companion is serious about something. And usually the answer is “sure!”, without even shadow of doubt, so we go away, reassured that we’ve got the deal.
Sometimes, though, nothing happens. I’m not sure, why. It may be because no one thinks I’m going to pull out their tooth for this (they’re right, unfortunately). Or there is some other reason, but it seems like the answer “yes” to the idiom isn’t taken too seriously.
But I found a solution. I just changed the price: instead of tooth I ask for, say, $100. And now they’re thinking before the answer. Which is, if you think it over, rather strange, because a tooth is obviously more precious thing than $100. But then, I will definitely not go for you tooth (see the previous paragraph), as for the $100, there are chances I will.
Or maybe the question isn’t too familiar and wakes our consciousness.
Anyway, that’s the trick I use now a lot and if you have similar problems, you may use it too.