Lego Duplo Train Track Switcher washable? / Best way to clean them? I've found some pretty old Lego Duplo train track parts, that I'm looking to sell on Ebay. 

As these are pretty old and caked with dust, I wanted to used my usual method I usually use to clean all kinds of Lego parts: Put them in a duvet cover with a zipper so they don't go everywhere, and put them in the washing machine, and wash without any detergent and no spin cycle. 

Afterwards I take them out of the machine (thanks to the duvet cover I can take them out just like a bag) and spread them on my terrace to leave them in the sun to dry. 

As these track switchers have metal springs in them (at least I think so, judging based on the sound when moving the red thing) I was not sure, if they were just normal steel or stainless. Does anyone of you know about this, or know a way to open them without destroying them?
According to this page it is glued together and can not be opened without damaging the part

You are correct about it containing a metal spring


I would just wipe it with a slighty wet towel