It blocks some cookies from being set in Firefox and Internet Explorer using well-known mechanisms, and it also adds entries to the Restricted Sites list (which only works with IE) and sets a bunch of ActiveX killbits in IE (but these killbits also protect Windows Explorer, the file-manager and operating-system shell); read my wiki entry on the program to see how to use it best:
http://code.google.com/p/jansal/wiki/SpywareBlaster
The short answer is that it doesn't work on any browser other than IE or Firefox (and its derivatives), but the ActiveX killbits alone are worth using this program.