We recently bought something that came with the following instructions.
(As you will see, it doesn't really matter what it was that we bought.)
Here are the instructions, copied exactly as printed:

NOTE:
WHEN YOU WANT TO PULL OUT THE PLASTIC GRIP, YOU MAY PLEASE PULL IT GENTLY;
BUT WHEN YOU WANT PLASTIC GRIP TO SHRINK IN, THEN YOU MUST USE YOUR PALMS
TO BEAT OR PAT SUDDENTLY ON THE CENTER OF PLASTIC GRIP THEN IT WILL SHRINK
IN SMOTHLY.  PLEASE REPEAT THE BEAT AGAIN, IF NECESSARY, TILL PLASTIC GRIP 
IS SHRUNKEN IN COMPLETELY.