Was this ground for divorce ever invoked, 1923-1970?

I have long considered the intricacies of English divorce law one of my topics of niche pedantry, and will happily, though perhaps not for my hearers, discourse of the errors made in historical fictions when invoking the dissolution of marriage as a plot-point. Also the sometimes curious lack of interest of biographers in how a wife had managed under a grossly unequal law to get quit of her husband. But I recently discovered a new twist.

I have somewhat belatedly been digging into questions a couple of people raised with me last year about Lord Dawson's contribution to the House of Lords debate on the Matrimonial Causes Bill 1936. This became the 1937 (Herbert) Act, extending the grounds for divorce beyond simple adultery in either party to include cruelty, desertion and insanity. In the course of his speech, Dawson said:

[I]t is an important omission from the Bill. In the case of homosexuality I shall ask that this be made a cause alike for men and women. It is time for equality in that matter.

 Except, I had been under the impression that homosexuality was not grounds for divorce.

However, on doing a little digging, one discovers that, going back to 1923, it appears that in theory at least, there was an anomaly that a wife could petition on the ground that her husband had, since the celebration of the marriage, been 'guilty of rape, sodomy or bestiality': but this would, presumably, mean convicted of a serious sexual crime and sent down for it. These had already been among the causes which, added to simple adultery, had provided women with grounds for divorce under the 1857 Act.

This does, though, rather preclude the kind of equality before the law that Dawson was positing, since lesbianism was not a crime under English law at the period - its depiction in literature (as in the case of The Well of Loneliness) might be deemed obscene but the actual practice was not illegal. The Amendment he suggested: 'has since the celebration of the marriage been guilty of the practice of homo-sexuality' raised considerable questions and was not accepted.

I do have remaining questions as to whether there are divorces on record in which bestiality or sodomy was the ground invoked, or whether, with the possibility of this coming into court, the husband just did not defend the action or did the stock collusive procedure of hotel room + hired co-respondent. I also wonder whether 'gross indecency' under the Criminal Law Amendment Act 1885 counted or whether a strict definition under the Offences Against the Person Act 1861 applied.