Clean up dirty picture books
At the flea market I bought some beautiful picture books with a smooth cover (coated cardboard)
They were very dirty - probably chocolate, biscuit pudding and what-I-whatsoever. I did not want to wash it off with water and experimented.
Best of all, I got them clean with 1 drop of scouring cream per side. With kitchen crepe kabe I really get rid of any dirt. Then rubbed again with a very damp cloth - great.