I think you should definitely send it in to be removed, whatever it is.
When I bought this watch online, it arrived with a speck on the underside of the crystal.
I tried to return it for another, but the seller said that was his last one, so because liked the watch so much otherwise, I just sat on it for awhile and one day took in to local watchmaker who removed the speck free of charge.
I can deal with a lot of wear and tear on my watches, but anything having to do with the crystal annoys me to no end.