I did have it fitted using just three rubber dampers for a while and it did certainly remove the humming noise, however seeking could still be heard slightly. What I'm thinking about doing, is getting a 1TB 2.5" laptop HDD, put it in a 2.5"->3.5" sound damping enclosure and fit the enclosure to the Scythe dampers and in to the 5.25" bay.
For the best sound damping, this is the right way, however it can't be done in most modern cases with quick release optical bays. It's also ghetto as hell and the elastic does wear out and need to be replaced after some time.