Even though I know they sell it in a liquid form, I always buy the aerosol version to support my local electronics supply store. What I do is attach the nozzle and then spray it into an empty liter bottle and then transfer that into an eyedropper. Then all I have to do is put 2-3 drops onto a qtip(cotton swab) and rub it onto the cart edge.
Yep, that's the best way to do it. Just get the DeOxit onto a cotton swab and then rub it over the contacts. They also sell the dropper bottles, and I find
this one particularly good for carts, but you pay more for the convenience. Spraying D5 into something, then using a cotton swab would do the trick, though
My method is pretty simple to clean a MVS cart:
Step 1: Use rubbing alcohol on a cotton swab until the contacts come back clean. This is to remove the surface dirt so I don't have to worry about wasting contact cleaner that is way more expensive than rubbing alcohol.
Step 2: Either apply DeOxit to the cart pins in a thin strip, if you're using the oiler bottle, or directly to a cotton swab and then rub it over the contacts, working one side at a time, until the swab comes back up clean (pink).
Step 3: Give the pins a nice puff of compressed air, and use a cotton swab to catch any stray liquid. There's always a little hiding somewhere.
Then it's into the Neo.