You need a real strong magnet for that. I tried it in my A+ Class last year (teacher had us do it). Not even a degausser will work, and that thing is one strong magnet.
Yep, it was fine. The free version only runs over the disk once with 1's and 0's but it worked fine for me since I didn't have any real sensitive information on my pc. Took something like 2 hours on my 500gb drive. Very easy, just boot with the disk in and follow the instructions.