litter boxes horse bedding; Horse bedding as kitty litter;

Question
Hello
   I took in a young cat to save it from my neighbor who was going to kill it because it was stealing his cat's food.
  I was surprised how tame it became and although we are not cat people it is becoming a part of our family.  It took to a litter box real fast but I asked someone how often you change the gravel.  The person said "Never, just scoop out the poop".  I have been doing this but am concerned about all that urine underneath.  It doesn't smell bad (usually) but sometimes it does.  Should I change the gravel every so often and how often?
   Also I have made the mistake of having kitty upstairs when we were eating and it goes crazy wanting food even attacking me.  He or she attacked me two times when I had food in my hands and it was a real wild attack. It's been three weeks and I still have the wounds.  I don't think he did it on purpose, just saw that food as a wild mouse outside.  Now kitty is in the basement when I am handling food.  Will this behavior go away?

Answer
Hi Don, Thank you for saving this kitty!  The Wild side of his behavior may go away in time.  Also, you will tame him a bit with the spay or neuter.
As for the litter box, yes the litter needs to be dumped out 1 x per week.  I don't keep my litter and just scope and scope.  The box also should be cleaned at least 1 x every 10 days with some clorox spray and then rinse.
I love this kind of litter... NOT litter at all, it's HORSE Bedding.
Works great - I scoop the solids out every other day.  
SEE here:
http://www.ehow.com/how_5888032_use-horse-bedding-cat-litter.html