"Thinking" Tempo

How do you get young students to slow down? Certain children love to speed through their playing. This causes, at best, the stuttering mentioned a few posts back, at worst, general frustration. 
 
But “slow down” doesn’t make sense to them! Their desire to speed precludes any logical thinking. Even when I manage to slow them down they don’t see the connection between tempo and success in a passage. 
 
One pedagogy mentor explained it this way: kids who have high energy, and love playtime, associate “slow” with one of two things. You slow down either when you’re tired, or when you’re sick. If I’m asking one of these kids to slow down, they think I’m asking them to be tired or sick, and why would they voluntarily feel like that?
 
I’ve had success with certain kids to play like a turtle. Occupying their imagination with thoughts of imitating slow-moving animals ‘tricks’ them into adopting a successful tempo.
 
I’ve been trying out one new strategy, one that I think will work best with 9 or 10 year old students (or older); kids that understand fast and slow, probably even know that slow practice is better, but choose not to do it. I ask them to adopt “thinking” speed. I’ll explain thinking speed as the tempo where their brains and their fingers can talk to each other. (Or if it’s a reading exercise, I’ll sometimes substitute brain for eye; for my Suzuki students it’s sometimes their ear.)
 
Again, the idea is to fill their mind with a different thought that inadvertently causes them to adopt a desired tactic.
 
I think with certain students, saying “slow down” causes a certain number of guilt, especially when they know that a slow practice tempo will be more successful. Using ‘thinking speed’ instead allows me to make a more neutral suggestion that gets the same result.