It's easy to remove the pump and close off the top to enable the bottle to be turned upside down. If you get the same brand there is no need to fix up a new top each time, just store your closed off top until needed.
Step 1: Take apart the pump
Step 2: Fill up the hole
Step 3: Glue the plastic into the lid
Make sure no glue gets left on the threads. I put the glue in from the outside to minimize this possibility.
Step 5: Turn bottle upside down
Other liquids such as shampoo or conditioner can be diluted and used up but diluting hand lotion would defeat its purpose.