Any decent de-greasing agent will work on the metal. Make sure you completely disassemble the rifle, especially including the bolt, trigger group, and things attached to the receiver.
For the stock, I prefer to wipe down with common rubbing alcohol and paper towels a couple of times a day for a few days until the towels remain fairly clean after wiping. You'll need q-tips and toothbrushes, of course. Easy does it around any cartouches and numbers/letters.
I also prefer satin finish Tung oil to BLO, as it is also mil-spec, and was preferred by the military if it was available, IIRC.
As for the sight blade being bent, all too common, and a real weakness. Bent it straight and see how it shoots POA vs. POI.If it's OK, buy a new blade with the same letter (= height designation) and pin, and you're good to go. If shooting too low, either get lower blade, or carefully file old one. If shooting too high, you need a taller blade.
Don't bother getting the usual front sight protector, as it has way too small an opening to be at all useful. Waste of time and money. Try to get the so-called USMC front sight protector which has a much bigger, and really usable globe. Good luck!