When I worked in a garage we threw the oil filters in the trash, we were pretty limited by city ordinances (That were very often in conflict with each other) on to how we were able to dispose of them. We did have one effective means of recycling them, though; one of the mechanics never could understand why people wanted a new filter when they did an oil change! After all, he reasoned, once you drain them all out it's just as good as a new filter. So he would let them drain all night and then take them home in the morning and use them on his family and friends vehicles!
Just another example of why mechanics aren't always the most reliable people when it comes to automotive knowledge.