I had no problem with Carefresh. I have two chinchillas, and the carefresh didnt make them smell at all, it actually improved the smell.
When I put new bedding in, my chinnies tend to go down and nibble on it. My male chin began acting strangely, like bloating, and I couldnt figure out what it was, he wasnt eating as much and didnt want to be touched. Turns out, carefresh is bad for them when ingested and this caused a slight blockage. The vet gave him fluids and I got Lifeline from Dawnna online and fed that too him a few times a day, and it worked miracles. I will NEVER use carefresh again. Thank god he only ate a little.
At the zoo though, we do use it in a tub with rocks in the ball python exhibit. He likes to go through it when hes shedding. =)
Thought I would share! =)