If you check on FinCEN's website for the SAR Activity Review Bulletins (latest one is at SAR Activity Review
you will see that over 400,000 SAR's have been filed for "BSA/Sructuring/Money Laundering" since April 1996. I highly doubt that the IRS wants to take phone calls on those.
IMHO, the best thing you can do to cut down on Structuring is to educate your local CPA firms about the forms that get filed when their customers deposit more than $10,000 in cash vs. just under $10,000 cash. I've informally talked to a couple of CPA's on the topic, and they were shocked to know that there is such a thing as an SAR.