Drat! Knelt on plasticine

[TrowelAndError]

I now have yellow plasticine ingrained in my smart work trousers. I hoped (in vain) that it might wash out. What shall I try next? I suppose I could scrub with a nail brush but am worried about creating a shaggy patch on the trousers.

If you get chewing gum on clothes, the tip is put them in the freezer and it will chip off.You could try that.

Yes, and if that doesn't work try the tip for wax. Cover with brown paper and iron.