Some helpful tips for odor control from a recent San Diego Rabbits Online Newsletter (thanks to Dr. Krempels for her
contributions to this list):
When you change the litter, be sure to rinse the box *thoroughly* with
water. Occasionally giving it a white vinegar rinse will help keep calcium
residues down and control the odor. Be sure to wash the bottom of the box as
well.
Be sure there is no urine *under* the box or around the boxes in areas
that are not wiped up. These get to smelling foul very quickly. If you do
have a spot where the urine tends to seep in, remove the box, scrub the area
thoroughly with white vinegar and rinse well with water. You might even want
to bleach it, but be sure to rinse away
all the bleach before you let bunny near the area.
Line the boxes with newspaper and a rabbit-safe litter, such as
CareFresh, Yesterday’s News (now available for rabbits), or Feline Pine. (Do
not use clay-based or clumping cat litter which can be dangerous for bunny if
consumed). Top off the litter box with a large handful or more of hay.
Bunnies like to munch on hay and use their litterbox at the same time.
CHANGE THE LITTER BOX EVERY DAY. If you line the box with newspaper, its
easy to dump the waste into a trashbag for disposal or use for composting.
p.s. Note that unneutered/unspayed rabbits usually have stronger smelling
urine than their neutered/spayed counterparts. Spay/neuter is highly
recommended for this reason, and to prevent cancers of the reproductive
systems, especially in female bunnies.