The best approach with any displacement method of excluding air is to decant into the next size smaller bottle as soon as the solution volume has been reduced enough. Even a pint bottle mostly full or marbles weighs a lot, and the surface area of the balls retains a lot of solution. A funnel with a gauze or grid insert helps to catch escaping marbles when pouring 8-)
I have seen people insert a plastic bag into a partially full chemical bottle and then use a funnel to fill the bag with plain water and displace air. The bag is then just rubber-banded over the neck of the bottle. Alright for a couple of days, but not a trick for long term use.