The rice box we use contains 80 pounds of rice, and very little comes over
the sides onto the floor.  I got one of the large, lidded plastic storage
containers from K-Mart last summer, and started with a single 20# bag of
rice.  It just covered the bottom of the box!  There now is about 8 inches
of rice, and a foot of sidewall to keep it from flying out when they play.
Next to the box of rice I have a lower box for them to use as a step stool.
They use the booster box going in, but when exiting, they usually just
climb over the side wherever they are and drop to the floor.
 
Our ferrets (total of 4) take turns being out in the ferret room and in the
cage.  As each pair is 'swapped', the newly released head immediately for
the rice box, where they always surf and snorkle.  During the day, ferrets
return to the rice box on a regular basis, sometimes alone, sometimes with
their buddy.
 
Buy rice - your ferrets will thank you.
 
Georgia - the left coast one...
[Posted in FML issue 2964]