Even with the drill mounted degassing stick it is quite common that you will have to degas over a period of a few days. Some people I have talked to have said they have gone into "weeks" (makes me wonder if their wine was too cold, etc).
The stir stick is definitely less taxing than 15 minutes of hand stirring for days on end, it just knocks out the revolutions in less time. Before I had my All-in-One Wine Pump it would take me 3-4 days with the drill mounted stick, and this wine was aged for a minimum of 6 months from the point of dryness before I attempted to degas. Anymore my wines are usually aged for 12 months and they have degassed on their own.
Before you make one compare to the price of a commercial one, you may find it easier just to buy one....but then again you may be mechanically inclined (I am not, to an extent).