You can't "control" a load with a contactor, without some way to control the contactor coil. A contactor simply connects/disconnects the circuit(s) when the coil is energized and de-energized. If there's not something or someone to control the coil, the contactor won't turn on or off.
In a contactor scenario, you would most likely have some form of switching mechanism that is unable to carry the load, like some sort of timer. The timer turns on the coil on the contactor, and the contacts close to make the 2 circuits contact each other to get power to the load.
btw, a Definite Purpose contactor is designed for a definite purpose, as the name indicates. In short, every contactor will be rated to turn on/off so many times before it is subject to fail. A DP contactor will be rated to fail at a much lower number of on/off cycles when compared to better contactors. I don't use them in every-day scenarios. They're the cheapest, noisiest contactors available.