How to remove plasticine from Lego Duplo?

[TheKitchenWitch]

That's it really.
I've picked off as much as I can, but there's still many little bits stuck to the bricks. I've tried soaking in warm water which didn't help at all (just made them more smeary).
Is there anything that's going to make the job easier?

I think it goes brittle in the freezer, so could you freeze the bricks for a while then try to scrub the last bits off?

I was so hoping there was going to be some magical solution that didn't involve filing the freezer with duplo.....:O

I found that getting a lump of plasticine and pressing it into the offending holes often managed to dislodge what was already present. (It sticks and pulls out whatever is stuck). Hard to explain without a physical demonstration.

Not when it's frozen, however - stuff in holes and grabbing lump both need to be softish.