Hi Med.
Glad you have found the input from us fellow shooters on the forum a help......... and are seeing improvements with your shooting.
I think a lot of us have been down the washing and lubing path........... as far as pellets are concerned.
Done it myself as have a few friends I shoot with who also tried it.
To be absolutely honest it does not make that much noticeable difference............save yourself time and money.....don't bother.
If however, you want to try it for yourself make sure you use the Napier pellet lube and NOT the oil!!
I also used WD40......a very small amount sprayed into a plastic bag..........add the pellets to the bag after washing /drying........... and gently/slowly roll them around inside to coat them.
Even weighed each pellet and batched them for more serious target work.......I was very keen back then
The JSB pellets are all lead....that is why you are getting dirty fingers.....dust from manufacture.........lead actually lines and lubricates your barrel.
Napier gun oil is fine.....or the gun wipes they make work well too for a wipe over and do last if you keep them in a bag.
Again.....DO NOT put any down the barrel or in the breech area where you load your pellet.
The Nikko scopes are good and the one you have chosen is ideal for you.......nice scope
The half Mil-Dot reticle is very fine.....but if you have good eyesight you shouldn't have any problems with it.
If you wear glasses I would lean more towards the Mil-Dot rather than the half.
Have fun using up your old pellets and be sure to keep us up to date with your shooting journey.