Bottle coupling/draining device

When employing viscous liquids dispensed from bottles I don't like waiting for the contents of nearly empty bottle to drain to the neck end before they can be used. To avoid this I will drain the dregs from nearly empty bottles into new (so nearly full) bottles. It takes some time for viscous liquids to fully drain from the nearly empty bottle so I made a coupler that allows me to join the two bottles together (with the nearly empty one uppermost) and so leave them unattended, coupled while the