Well, you didn't really address anything I brought up. Ive been examining the green on a few carts and it appears to me your "green mold" is most likely a patina forming. I wouldn't really say you're doing anything more than speeding up the inevitable by blowing on the cart. Whether you blow or not, 20 years its going to happen unless kept in very controlled conditions.
A patina is actually a valuable asset, in fact the most valuable asset of almost any collectible/antique. Not that this applies to electronics... It does however, in many environments protect from further damage. For all we know this could be the reason some carts still work after a good cleaning
OK
I blow on the cart after trying everything else and it magically works. I play for a couple hours, turn off the system and the game still works the next day. I just did this bucko... Id be very sure in saying if I turn it off for longer and let it sit for a week it will still work. Now tell me how does this minuscule film of moisture keep for 24 hours? Even one hour?... All Im saying is that you turned one possible myth about dust, into an even more improbable myth about moisture being responsible for the phenomenon...
Id like to try compressed air... But there is moisture in it... and I believe a can o air most likely condenses moisture in the air a bit as the gas expands.
I did however order an original NES cleaning kit after discovering your thread. Even tho 90% of my carts work in my very clean system sometimes blowing still does the trick. Im hoping the NES kit will work.
BTW I never said it wasn't doing any damage, I am simply addressing the obvious flaws in your moisture and green mold theories. You keep bring up green mold, mildew and "growth" in various threads. You do realize that fungi have very specific environmental conditions right? They require very high humidity, the right temp, and more... notice that they only grow in certain places in your home? Unless there is mold growing on the walls in your living room or where ever you're keeping you collection, most likely the conditions required will never be met inside a NES cart.