Is this alright for the demagnetizing? Bit more economical.
http://cgi.ebay.co.uk/Defluxer-Demagnetizer-Wearite-Ferrograph-instructions_W0QQitemZ120452785364QQcmdZViewItemQQptZUK_Consumer_VintageAudio_RL?hash=item1c0b8ba4d4&_trksid=p3286.c0.m14
The compressed air is about three times more expensive than it was a year ago when I got a can to clean my computer so I am just going to vacuum the dust out carefully.