Its a bit like those water based kids crayons designed to be easily washed out of clothes. Never so easy on carpets esp wool.
Unless you can charge for trying I wouldnt bother.
Ah tell me about it!
I have had better success getting dulux paints out of carpets than what I have getting Early Learning Centre paints out. And that stuff is for kids to experiment with.
And of course the parent says "it's only childrens' paint"