One thing to consider about plating holes, so far as I know, is that the plating in commercial processes is generally done before circuit etching. Otherwise, getting an electrical contact to each hole may be challenging.
Another approach may be to simply prepare the board as usual, drill the holes, then use a reactive silver paint to "plate" the holes. In the past year, two such paints have been developed based on the Tollens reaction.
In the first reference, silver acetate is prepared and when heated in the presence of ammonia is reduced to silver. In the second article, diethylamine is used to produce formaldehyde upon heating, which then reduces the silver. ACS used to have the full abstract of the Walker and Lewis paper, which has sufficient experimental detail to repeat the results. Unfortunately. that abstract seems to have been taken down. Nevertheless, here are the references for those who may have access:
1)
http://pubs.acs.org/doi/abs/10.1021/ja209267chttp://news.illinois.edu/news/12/0112ink_JenniferLewis.htmlCitation: Walker, SB and Lewis, JA; JACS 2012,134(3):1419-1421.
2)
http://pubs.acs.org/doi/abs/10.1021/am302505j"DEA in the silver ink decomposes at temperatures higher than 50�C and
generates formaldehyde, which reacts spontaneously with silver ammonia ions to
form silver thin films." (Chen, S-P, et al., November, 2012)
Although the films are thin, they are highly conductive and might be suitable for conducting signals in a double-sided PCB.
John
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