I hope that the main point - that junipers will not survive indoors - was taken seriously. The "white stuff" might also be a form of mold caused from over watering, poorly draining soil and indoor living (poor lighting, poor air circulation, 'unnatural' air-conditioning, constant temperatures with no overnight variations, lack of winter dormancy, etc.
As a truly hardy outdoor tree this juniper may have been suffering a slow death indoors. Hope it is not too late.
Please let us know with an update.