I would not recommend this practice for a couple of reasons:
1) As the prop moves through course pitch towards feather, there will be a "surge" of thrust as the AoA of the blades increase.
2) If this practice becomes habitual, then one day on a contaminated taxiway, the pilot will go to feather and as things never happen quite symmetrically on twins there could be the chance of a loss of directional control.
Personally I hate it when pilots try to reinvent the airplane and start making up their own little techniques. Just operate the plane the way it was designed and stop mucking around.
