It would work to some extent. The thing to consider though is the cost of the pump as a simple powerhead woudn't do it, you'd need a pump that can generate upwards of 50-60 PSI of pressure, and the wear on your membrane. The waste water contains everything the membrane removed from the product water, so putting it through again would be harder on your membrane.
What I did is run the hose outside of the house and I fill a large barrel with it and use the water to wash cars, water flowers, etc. To me that seemed the cheapest way to use that water for something useful.