We've got this pink stuff in the UK called Muck Off and it's great at ..er.. getting the muck off. Doesn't smell too bad and is made from stuff that's kind to the enviornment too so you can really slop it around.

Otherwise, have you tried windscreen wash for cars, undiluted? When I was a student the lino floor in our kitchen was criminally dirty, so I went through the whole cupboard trying different things and found the screen wash got the grease off like a dream! Not sure how good it was long-term for the flooring though - but we'd moved out by then