You won't find this in your favorite supermarket tabloid. My research took me to Robert Graves' superb telling of The Greek Myths (Penguin Books, 1960, two volumes). Graves devoted more than 120 pages to Hercules' long, convoluted career; I have boiled this down and extracted the TG bits.

Hercules, the son of Zeus and a mortal woman, was one of the most prominent characters in Greek mythology. As the curtain rises on our drastically condensed tale, Hercules has murdered a man who was his guest, thus violating the code of manners of his time and earning Zeus's great anger (Zeus was no morality role model, but he had some standards and he was rough on those who didn't meet them). An oracle advised Hercules that there was only one way to cleanse himself of guilt and get back in Zeus's good graces: he would have to allow himself to be sold into slavery for a year, contributing his purchase price to the children of the man he'd killed.

Hercules agreed to this and was quickly purchased by Queen Omphale of Lydia (a kingdom in what is now western Turkey). Although he performed a number of heroic deeds--both military triumphs and feats of strength--during his period of slavery, Omphale had purchased him as a lover rather than a fighter, and she bore him several sons over a period that came to exceed the original year.

Omphale liked to amuse herself with Hercules, sometimes requiring him to wear women's clothing and do women's work (an early version of the familiar forced-crossdressing tale). According to reports that got back to Greece, Hercules had cheerfully exchanged his trademark lion pelt for a yellow petticoat, a purple shawl, a girdle (a belt-like outer garment rather than a foundation), jewelled necklaces, golden bracelets, and a woman's turban. In the midst of Omphale's serving girls, he spun wool into yarn while his mistress wore his lion skin and brandished his weapons.

Just vicious rumors, Graves assures us. The real story is more complex. It seems that Hercules accompanied Omphale on a visit to one of her vineyards. She was regally dressed in a purple gown with gold embroidery--a dazzling sight--and the god Pan, seeing her from a distant hilltop, fell in love with her and followed the couple on their journey.

When they reached their destination that night, Omphale and Hercules amused themselves by exchanging clothes. She dressed him in her purple silk gown and her girdle and sandals--much too small for the mighty Hercules. After dinner, they retired to separate couches, as they had planned a dawn sacrifice to the wine-god Dionysus, who required some minimal degree of purity from his devotees.

This story more or less telegraphs itself. The lamps went out and Pan sneaked in, fumbling about in the dark. Identifying his beloved's couch by the silks worn by its occupant, he untucked the bedclothes at the bottom and eased himself in. Hercules, awaking, drew up one foot and, with a mighty kick, sent Pan hurtling across the room. Omphale called for lights, and when the servants brought them, she and Hercules found Pan crumpled in a corner, bruised and confused. They laughed uproariously, but Pan failed to see the humor in all this, and he was the source of the report that went back to Greece, outing Hercules as a habitual and perverse crossdresser.

If Hercules' career had featured only one crossdressing incident, his TG credentials might be in doubt--but there was another event. After completing his service as a slave, and following a series of additional adventures, Hercules was caught in a fierce storm at sea and was shipwrecked on the island of Cos. He and his shipmates soon found themselves in a fierce battle with a group of locals. Exhausted by the storm and badly outnumbered, Hercules broke off the fight, fled to the house of a "stout Thracian matron," and made his escape disguised in her clothes (we can speculate that she and Hercules were both 20s, whereas Omphale was more like a 10).

Later that same day, refreshed by food and sleep, Hercules returned to battle against the men of Cos and defeated them handily. Then, still in stout matronly garb, he married Chalciope, daughter of the just-deceased king of Cos. According to Graves, this explains why the bridegrooms of Cos thereafter wore women's clothes when they welcomed their brides to their homes.

This is all that the myths have to say about Hercules' public appearances en femme. We can only speculate on what he may have done in private (or on other occasions when he wasn't read).

When the Southern Baptist Convention realizes just how much Disney left out of the story of Hercules, perhaps they'll rescind their anti-Disney boycott. But perhaps we should be boycotting Disney...