I've just been readnig Jerome Neyrey, Paul in Other Words, 1990, in particular the section on "Body Language in 1 Corinthians," (pp102-46). Like Countryman, Neyrey makes extensive use of Mary Douglas' work on purity. However while Countryman shows how Jesus and Paul radically reinterpret (or even subvert) the ancient Hebrew conceptions of purity found in the Torah, Neyrey seems determined to shoehorn almost anything Paul says into the polarised anthropological model he has distilled from Douglas. Paul is thus portrayed as an authoritarian obsessed with physical and social purity.
As far as my own research goes a crucial illustration of the sort of thing Neyrey does that I dont find convincing is his treatment of 1 Cor 5-6. Countryman observes that the common theme is that of property rights, the incestuous man has not respected his father's sexual property by having sex with his step-mum, other Corinthian Christians are taking their brothers to court to defraud them of their property rights, and Christian men are visiting prostitutes (or being tempted to do so) and thus defrauding God of his property rights over their bodies (Countryman 195-6).
But for Neyrey 1 Cor 5-6 are held together by Paul's obsession with genitals as the marginal points of the body (Neyrey, 114). That proposal fails because it cannot explain the presence of the discussion of law suits and neither does it account for the way Paul treats each of the "sexual" issues. In treating the sexual issues of 1 Cor 5-6 Paul shows no concern for the mechanics of sexual purity but is deeply concerned about those who have what they should not (their father's wife or their brother's property) or who are being had by whom they should not be had (prostitutes!).
Regarding social purity (1 Cor 5:6-8) the isue is not so clear cut, but it is worth pointing out that Paul's primary concern seems to be that the offender is brought to repentence and thus "saved in the day of the Lord." The remarks about the leaven might refer to the man's offense but more probably refer to the communty's "boasting." It would not be then that the offender was tainting the community but that the community's boasting was. After all in the NT the sin of others has lost its ability to stick to us (cf. 1 Cor 5:10) but our boasting (and resultant pride) can have terrible effects.
The following section (1 Cor 5:9-13) about judging immorality is then an expression of concern that those who are living destructive lifestyles are brought to repentance through ostracism. That may sound funny, but notice how not eating "with such a one" is not to avoid contamination but to bring them under "judgement."
Let me know what you think :-)