I use it for my basses and guitar. And it perfectly works regardless material of strings (tried with nickel, chrome and steel) and roundwound of flatwound. Great thing is that it does not affect fretboard material ? maple, rosewood, ebony? It makes it in good shape anyways. So you may no worries for your oiled maple fretboard.
I found it a bit easier to use than cleaner by Dunlop because the applicator stays wet for all time, no need to shake as with Dunlop bottle.
It is definitely not the thing that make strings last forever, but it can helps out for gig or some demo recording if you need strings to sounds almost like new.