Half Cent Connundrum; To Oil, or Not to Oil?

[Frank]

Here's one of my late-last year acquisitions...a cool 1806 ½¢.

I could tell from the sellers' pictures there was some sort of doo doo on her...but being the ever-optimistic Numismatist that I am I bought it for $27.50.

Judging from the aforementioned sellers' pictures...I could also see some pretty heavy-duty detail under all that mess.

Original Pictures (modified by me, so as not to infringe):



Whatever the substance is, it breaks 'clean'... in this instance meaning the edges are sharp. Which to me puts it in the resin (natural or not) category.

Now after soaking her in EVOO for about two weeks, there's little progress if any. Should I just leave it soak for a few months (had to do this with an 1804 I owned previously), or might there be another technique some of you may know to speed up the process?