Mellotronists

I have been looking for a demagnetiser in Toronto....Retailers don't 
have them.  Any ideas?

I have a battery operated cassette shaped demagnetiser.  It turns on 
as the cassette tape head moves to the play position. (A small spring 
switch in the demag-cassette).

If I press this switch with a cotton swab close to the 'tron 
heads.....  Would that work?

Clay