We have installed the maibec eastern white shingles on our home and would like them to turn silvery grey, the weathered look you typically see in Marthas Vineyard. However, we are not on the beach, and since we are in California we don't have much rain. What would be the best way of achieving this? From my research, these appear to be the options:

1) cabot bleaching oil (we would have to source this out of state)
2) cabot bleaching oil + weathering stain (also source out of state)
3) leave it natural (will it mold/rot? turn the wrong color?)
4) apply a transparent stain (we have a sample (using driftwood color by Cabot on a shingle but it still looks like paint)

Thanks so much in advance!