I have a source for oak shavings. I have tried them and found they are more absorbent and keep the smell down better. However I currently do not use it because my source does not eliminate the dust. I am planning on building a cyclone separator to eliminate the dust. Until then we will continue to use pine. Also go to the sticky I think is located in the DIY section and find the plans for a odor absorbing air cleaner using phosphorous activated charcoal. That helps remove the ammonia from the air which is 60 to 70% of the smell.