Veet, a very similar product, kept my arms and legs relatively hair free for a week to 10 days. I never tried it on my chest, but I plan to once I return to school, where I left the bottle.
And to add on to what Cindy said; the skin in the face is also more delicate, these chemichal hair removal products can not only blind you if you get it in your eyes, but also does not do well for the skin either. You're better off just shaving with a razor.