Can 'Zefal All in 1' really doall of those: cleaning, degreasing and oiling? Can someone tell me if 'Zefal' All in 1 Spray is good for: degreasing, oiling and cleaning? Link

It seems suspicious because it covers 4 very distinct functions in a single spray; eg: Degreasing, Oiling, Cleaning.

What do you'll think? 

I just got a beautiful bike yesterday, powerful and smooth pedalling. However, it was very neglected and needs cleaning and rustproofing. However, as a student I don't have a tremendously large budget and this bike needs some other purchases too.
In general, it's better to avoid spray-type lubricants like this one (plus, it won't do any of the functions described well). They have a tendency to go in places you don't want to go. Look for drip bottles, such as this one: 



If you're on a budget, good old 3-in-1 multipurpose oil is about 2 dollars (versus bicycle branded ones being about 5-6 for a lot less). It's better than nothing. 



If you need to restore things like a rusted chain (and for some reason don't want to spend the 10 dollars to replace it), you can clean the rust off with citrus cleaner or mineral spirits then oil it. Bits of rust on the frame aren't really a big deal unless they're huge amounts bad enough to have structural effects.