It all started so well

[ntpntpntp]

Yes you need to wipe off the grease from pickup wipers and contact pads. Use a cocktail stick as NPN suggests, or something lint free like a strip of old handkerchief twisted up into a stick.  I would advise against cotton buds as the fibres too easily catch and pull off into the mechanism. 

These days I use Labelle 106 PTFE grease on gear trains rather than oil. Just a tiny amount on the end of a cocktail stick.  Run in at slow to moderate speed to begin with so the grease spreads around the teeth and doesn't fly off everywhere.

I've had brand new Continental models turn up with similar problems of over-greasing. Fleischmann and Minitrix.