I have probably 300 CDs / DVDs that have been sitting in the office for years that I want to dispose of ...

They have all sorts of client data on which means I'm not happy to just dispose of them in landfill ...

Any suggestions on the best way to destroy the data risk?

My best idea so far is to put them on a steel rod in a huge stack and then blow torch the edges so the are unreadable ... any better ideas?