I use mine to run out of the water. Water will also exit the drive inlet when using this, since there is no check valve to keep that from happening. Basically, as long as you're at idle or thereabouts, there's enough water being sucked into the cooling system to make this work for running out of the water, as long as the raw water pump is good.
First, use compressed air or a leaf blower to blow into that hose. This will force any water that's in the loop coming from the outdrive out through the drive inlet. Next, drain the block, manifolds and risers by removing all drain plugs. Be sure to poke into the drain holes to ensure no sediment or rust particles is clogging the holes. I usually keep the drain plugs out for the winter. Remove the hose which goes from the raw water pump to the thermostat housing and drain all water from the hose. Remove the large hose which connects the water pump inlet to the thermostat housing outlet from the thermostat housing, and drain the water. Use a funnel to pour a few quarts into that hose in your picture, then crank the engine for a few seconds to suck antifreeze into the raw water pump. This will draw antifreeze into the remaining places that water may have remained, keeping you safe for the winter.
It's a good idea to also remove the spark plugs and spray in some fogging oil, then replace the spark plugs.
