Dean,
What results did you get from what method?
I've used it in the past for getting rid of concrete cancer (minerals deposited by rainwater coming down the building and going on the glass), but that was before I knew about MDR.
I was told to moisten an old scrim and dip it in the rouge, then apply to the glass and rub over the waterstain, the moistness of the scrim made it into a paste. There's no way jeweller's rouge will take out scratches - it's used as a polish, similar theory to T-Cut for paintwork on your motor - if you can hear your nail going over a scratch on the glass it's beyond repair. Unless you use the "StoppedScratchedGlass" website machinery, which looks likely to be dearer than replacing the pane.
I still recommend the plastic stick-ons!