IMO it's a bad idea, especially if you use the needle from each to draw from the bottle, then it has lots of time for any bacteria it came in contact with to grow. I realize that the time it takes to pin you will not technically have a sterile pin just from the air, and that realistically it's not going to be a problem.
The reason the plungers stick is BB will dissolve the rubber on the plunger, and it will dissolve so your oil will still look fine. It only takes a second to draw, use an18g pin to draw then attach your pin for inject. Just preloaded it the night before, instead of weeks at a time.
Before anyone gets all excited it's my opinion, I know lots of guys who do this with no issues, but I also know guys who use the same pin 3-4 times with no issue, it's just not for me and I have pinned multiple compounds daily for long periods of time plenty of times.