In Ms Holmes of Baker Street: The Truth about Sherlock C. Alan Bradley & William A.S Sarjeant argued that Sherlock Holmes was actually a woman and that her mood swings could be attributed to her periods. In their book they attempt to show
“evidences of Holmes’s feminity which might equally well be regarded as indications of homosexual proclivities. That alternative can, we feel, be disregarded in view of the evidence presented, not only that Holmes suffered from the physical vicissitudes to which all women are subject until released from them by menopause, but also twice became pregnant.”
Samuel Rosenberg theorised in his book Naked is the Best Disguise that ‘The Red Headed League’ was actually about the prevention of homosexual rape. Christopher Redmond discussed this in his book In Bed with Sherlock Holmes in the chapter ‘A World Without Women’:
“…one must consider the opinions of Samuel Rosenberg, the frequently reviled pioneer of Doylean criticism to whom nothing is scared and all is Freudian…He finds great significance in the scene that has Fleet Street clogged with men all bent on a single object, and he uses the first name of pawnbroker Wilsen (Jabez is the town where lived the scribes – I Chronicles 2:55) to connect the encyclopaedia-copying redhead with a scene in the Old Testament (Genesis 19:4-11) in which men converge not to apply for a job but to attempt homosexual rape on two exquisite creatures who are in fact angels. Rosenberg goes on to stress the ‘womanly’ character of John Clay: Watson actually uses that word, and there is mention of pierced ears and other effeminate characteristics. Finally, he identifies the pawnbroker’s ship and its three hanging balls as ‘a symbolic area of unhappy homosexuality‘ and the bank’s vault as a ‘cloacal cellar filled with fecal gold‘. The result: the planned robbery is symbolically a homosexual rape, and Holmes thwarts the perversion as well as preventing theft.”
Redmond goes on to say
“This analysis, though it may sound both far-fetched and distasteful, is supported by many details in the story, from Holmes’s affectionate reference to Watson early in the story as ‘my partner and helper’ to the gratuitous reference to the sexual ambiguousness George Sand at its very end. And, as already mentioned, there is the absence of women even in supporting roles, to which Holmes draws particular attention: ‘Had there been women in the house, I should have suspected a mere vulgar intrigue. That, however, was out of the question.’ It will certainly appear far-fetched to use it as the basis for an allegation that Holmes is drawn as homosexual, or that Doyle deliberately wrote a story with homosexual motifs.”
You could probably write an entire thesis on Christopher Redmond’s often problematic attitudes towards homosexuality and women in his books on the canon but I’m not clever enough to do that, but I thought people might interested in seeing some of the stranger scholarship out there.