If you don't have a binocular microscope and some
good needles then leave it be. If you have a lot of experience with a SBBB then use that under running water. Otherwise, leave it be. Its identifiable, in
good shape and looks
good. If you're
still dead set on getting that off then stick to the classic distilled water soak and toothpicks. Its a slower but much safer method that will
work on lime/calcium... I'd personally avoid the olive oil, stick to distilled water changing the water every 3 days and less than 10 minutes of tooth picking between changes. It'll take months to
work but without the proper
tools thats the safe way to do it.