Yes you can use reverse, the one-way only affects the front wheel.
A one way diff contains two one-way bearings, which mean that the front wheels can freewheel individually faster than the rear. This acts as a kind of substitute for a third differential, and lets the car corner faster without the tyres scrubbing (the front wheels need to turn faster than the rears for efficient cornering, a standard 2-diff car can't achieve this)
When braking and coasting, the only braking effect is on the rear wheels, this can make the car unstable, and also serves to sharpen the steering.
On power, when the wheels are spinning, the diff acts like a solid axle, which can pull the car around the corner, without "diffing out".
A one-way pulley has similar effect, but less pronounced, as the retention of a front diff adds some stability.