Every time I replace my rotary blade, I think to myself "I need to do this more often!"
When I bought replacement Olfa blades on Amazon, I noticed the packaging was all in Chinese - except for the word "Olfa." So, next time I went straight to the source and bought them from Aliexpress for about half the cost. As much as I hate to throw away the dull blades and would like to find a quick, easy and economical way to recycle them, I suspect it would cost more than just buying more blades.