oil makes a mess, but it protects it... that's why mine gets copious amounts of wd40/gt85 sprayed at it over winter and comes out the other side looking no worse.
Just is a bugger to clean off when spring comes.
trick is never ever ever ever ever clean the thing.
but, the state of my bike atm, well I've seen cleaner tractors come out of fields after muck spreading.
But I like most things dirty.
Proper Scot-oil stuff is just too expensive for what it is so, I was using chain saw oil in the Scotoiler for about 18months (20k miles) went through about 1.5ltrs of oil @ £6 a ltr. made a mess, was an even bigger PITA to clean off (if that's your thing) and just made the crud stick to the chain and make grinding paste after a while. (I do clean and manually re-oil my chain every couple of weeks)
Now I use the large supply of used engine oil I have accumulated in the last year, about 15ltrs of the stuff. If anyone wants some I'm your man! (I will not be using the used Diesel engine oil from the mrs car- way too naffed)