Carpet cleaners

Viberduo

I bought a Vax carpet cleaner refurb from Argos just after Christmas, was about £220 new but £40 refurb, havent got round to using it yet as dont know the best(and cheap) stuff to use.

My carpet is a orangey brown colour, was new when I moved to flat, looks ok for the most part but some areas like corners and edges look darker than main area, and a few sticky spots round where I sit(probably spilled food I have stood onto carpet) and my friend spilled some sauce on carpet before which I cleaned off but the carpet looks darker around it, I have 2 small stains where I knocked comptuer fan over and the grease got on carpet(which is probably the hardest stain to remove)

In the spare bedroom the carpet looks so much lighter because I only have relatives round like 2 nights a month and a friend comes round once every 2-3 months for 2 nights(and I spent a few hours in there once when it was a nice day)

Will this cleaner be effective? And even if it is for the most part what about the 2 small grease stains?