check out the website for customer rewards and loads of info.
http://www.worldsbestcatlitter.com/Home/default.aspx
I have two kitties and we have septic (not city sewer) and no problems so far! I scoop and flush whenever I see someone has gone. I use the mulitcat strength and LOVE the smell fresh out of the bag! how some can say it's awful, I don't know. after scooping a poopie, since my kitties don't cover that, the room will still stink, so I spray Stink Free Spray Powder Deodorizer and sha-zam! no evidence of cat stink at all! you can also use Oust in the room, but a little shot of the Stink Free in the box where the poop was works the best.

Called the Stink Free people to check on danger of spray going my septic, since you spray it on the flushable litter. They said it was perfectly safe because all it is essentially is talc. I suppose I will catch flack on here now for using talc...

personally, using the nonflush kind is just out of the question for me now. i love only having to deal with cat crap one time and then it is gone forever! before it would sit in trash somewhere, penetrating any trash disposal wrapping method i could find, sinking and rotting waiting for trash day. ugh!

also wanted to mention, it says on their website, you don't ever have to start it over! i emailed and asked if that was really true?! according to their little chart (see FAQ page), the big 17 lb. bag should last me 26 days. can't recommend this enough. fabulous!