Are Crayola Erasable Markers Worth it? Do they actually work?

I was thinking of buying the Erasable Markers for School work, so I don't have to redo a worksheet or when I mess up and get a bad grade on a mapping worksheet and what not. I was just curious if they actually work and if the colors aren't too light. I have the erasable colored pencils and I love them for school work but not for actually coloring in a picture because the colors are too light for me.Thanks!