Whilst Jeannius is generally correct in saying it makes no difference for most low speed manoeuvres I do find the ability to use prop flow over the rudder handy in some cases.
If you turn the wheel
hard to stbd and then give the engines a quick burst of ahead the prop wash will tend to force the stern across to port with very little fwd motion. With judicious use of fwd and astern it is possible to move our boat sideways with very little fore and aft movement. This can be very useful if parking in a small gap alongside a wall for instance. It is also quite handy when coming alonside a pontoon - aquick burst of power against the angled rudder can push the stern towards the pontoon to make getting off very much easier for the crew.
Although not used very often this technique is very a very handy weapon to have when you need it. I am sure you can acheive the same end without the prop wash but it will be a bit more difficult.