I think i will take them all out to clean.

Yep , very good idea to take the time to overhaul all score reels , they are probably the hardest working parts of any EM pinball .
Just do one at a time so you can refer to one of the others to put it back together properly . You will find they are easy to do .
Also , pinball machines are designed to run without lubrication .. never use WD-40 etc on a pinball .
I do , however, put a light smear of Superlube on moving parts when I overhaul them .
Superlube is synthetic and designed not to attract dust and dirt .
If you get keen , pull apart each of the mechanical parts (eg slingshots etc) as well and give them a clean .
You will find the game will play faster and better if you take the time to do this .