This is a quick hack to get your money's worth out of the mostly empty bottles of dispenser top liquid soap many of us have in our bathrooms.
The first steps will be to round up at least two bottles, remove the dispenser tops, and pop the pump assembly out of the screw-on ring. This may take a bit of force, but with the particular brand I had I was able to easily force the pump assembly out with my thumbs.
Next, take a small amount of Sugru, roll it out into a thick line and wrap it around the join of the two screw-on collars.
Once set, you should be able to screw the two bottles together and watch as all the last drips of soap are pulled down into the bottom bottle.