With the funnel and eyedropper, I can add 10-15 drops of fluid, then empty the remaining into the bottle. I then use the eyedropper to BLOW air into the funnel to clear any bubbles that may have formed.
Really NOT a big deal and works for me!
Better NOT to over-think this issue.
MOST times, LESS is MORE!
Just like folks over-cleaning track or over-thinking lubrication - track cleaning is overrated and many people tend to over-lubricate!