Removing silicon oil from sandstone

Does anyone have experience of trying to remove stains caused by
silicone oil from soft sandstone?  My problem involves trying to
reduce staining caused by cheap silicone caulking (the type used to
seal bathtubs, sinks and such) used in contact with sandstone.  This
caulk has been applied to a rock face outdoors.  It is not on a
small object that can be moved into a lab. Thanks,

J. Claire Dean
Dean & Associates Conservation Services
3438 NE 62nd Avenue
Portland, Oregon 97213, USA
503-331-1972
Fax: 503-331-0762

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                  Conservation DistList Instance 11:14
                 Distributed: Wednesday, August 6, 1997
                       Message Id: cdl-11-14-005
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