Doing one at a time, you can still degrease the fretboard with lemon oil as you go. Between restrings, I can recommend fretfast. Been using it for donkey's years.

I have been reading elsewhere where people say putting goo on your strings impairs the sound. All I can say is violins, voilas, cellos and basses all have sticky resin drawn across them from the word go and tend to last just as long as guitar strings before degrading....

On a practical level, you can give yourself a sliding scale of string quality to time. So forking out on Elixir strings and changing less often is a similar cost to cheap Martin strings and changing more frequently. I advise people to check the sound after a few days as a comparator rather than price and reputation. If a cheaper string changed more often sounds better, go for it. I have owned many guitars and even now, a custom made one I have had for two months? Still not sure which strings I will settle on. Whereas my workhorse guitar has been on Elixir Nanoweb for three years now and whilst I occasionally try something else, I keep going back to them for that particular guitar. Another guitar seems to prefer the cheaper bronze D'Addario.

The common link is that my method of changing, two at a time (some manufacturers coil 1st and 4th together etc and I got used to it) is common to all of them. Mandolins get them all removed for ease of cleaning the rather than any other reason.