The above method doesn't work and does nothing to conserve battery life. The only thing it does is disable the metering system from turning on when you press the shutter button half-way down.
However, battery technology has come a far way since the 80'ies. You can replace the SR/LR44 button cells with single-cell 3 volt Lithium ones which last a lot longer. My OM-3 "runs" for months at an end with such a cell. And my 4Ti hasn't needed a new cell for 14 months.
AFAIK the OM4Ti never suffered from this problem and I suspect the OM3 didn't either. The latter I really do not know. May be someone more knowledgeable can shed some light as I own one for some days now