A.P.
I used frozen baby wash clothes, cold fruit in the mesh feeder bags, frozen bagels...this was a favorite. My son would gnaw and gnaw and gnaw and when it became too gross I would just throw it out. He also enjoyed a vibrating teether, especially for those back teeth. celery sticks were good too, he couldn't bite through them but he could move them around and chew where he needed to.
We also used Humphrey's teething strips. I only found these at Walgreens. They were wonderful!