double-handedly

Using two people.

Dinghies are designed to be sailed single-handedly or double-handedly, but some larger cruising dinghies may have room for four or more people on board.

Using both hands at the same time.

Working double-handedly also conserves your hands in large kneading strokes, for example when you are working on the adductors on the inside of the thigh.

By means of two approaches or agents

I said I was writing my memoirs, a choppy musical dedicated to counterpoint, without the axes of time and place, collapsing in upon itself because the notes will inevitably run out, returning, elaborating, crisscrossing, double-handedly creating variations upon a theme.

The combination of discontent and economic collapse brought about the revolution. It did not do so simply double-handedly.

Duplicitously or hypocritically.

NATO works double-handedly against Albanians and Serbs.