Yes that should work - all you have to do is call TurnOnScreenSaver when you want to use it.
For example:
private void button1_Click_1(object sender, EventArgs e)
{
Timer t = new Timer();
t.Interval = 2000;
t.Tick += new EventHandler(t_Tick);
t.Start();
}
void t_Tick(object sender, EventArgs e)
{
Timer t = sender as Timer;
if (t != null)
{
t.Stop();
}
TurnOnScreenSaver();
}