Instead of Sawdust, you can try using Playsand. I have been using it for years and my hamster love it. This is the brand I have been using:
Quikrete® Play Sand (1113-51) - Concrete / Blacktop / Sand - Ace Hardware
I have seen it sold at Ace Hardware and Home Depot...so it is pretty common. About $5 for a big bag of it. One bag usually lasts me 2 or 3 months at least.
It is clean, as it is intended for children. It seems to suppress moisture and odor. I treat it like kitty litter...I do a partial change once or twice a week with a vacuum and a full change about once a month.
I have tried several different types of bedding, and the hamsters seem to like this the most because they can dig in it. Here's a pic of my current set up with sand:
The top cages have carefresh bedding. The aquariums have the sand. But they seem to prefer the sand.