Has anyone read the poem Sweeney Among The Nightingales by TS Eliot?

Question

I'm an English major, but analyzing poetry is not something I'm good at. In the last two lines of the poem "And let their liquid siftings fall/ To stain the stiff dishonoured shroud." my professor is saying there is supposed to be double meaning in "liquid siftings," I get the literal sense of the words, but what other possible meaning can you contrive from that line? Long analysis short the narrative is about a bum, whom Elliot compares to the legend of Agamemnon, a Greek king around the war of troy, they are both killed by their lovers and both have Nightingales sing after their death. Elliot seems to think that bum's and kings, once they reach death, nobility is stripped away and they are equals.

If anyone can help me with this I'd appreciate it. Thanks.

Heres the rest of the poem sorry.
APENECK Sweeney spreads his knees
Letting his arms hang down to laugh,
The zebra stripes along his jaw
Swelling to maculate giraffe.

The circles of the stormy moon
Slide westward toward the River Plate,
Death and the Raven drift above
And Sweeney guards the hornéd gate.

Gloomy Orion and the Dog
Are veiled; and hushed the shrunken seas;
The person in the Spanish cape
Tries to sit on Sweeney's knees

Slips and pulls the tablecloth
Overturns a coffee cup,
Reorganized upon the floor
She yawns and draws a stocking up;

The silent man in mocha brown
Sprawls at the window sill and gapes;
The waiter brings in oranges
Bananas figs and hothouse grapes;

The silent vertebrate in brown
Contracts and concentrates, withdraws;
Rachel née Rabinovitch
Tears at the grapes with murderous paws;

She and the lady in the cape
Are suspect, thought to be in league;
Therefore the man with heavy eyes


Leaves t

Declines the gambit, shows fatigue,

Leaves the room and reappears
Outside the window, leaning in,
Branches of wistaria
Circumscribe a golden grin;

The host with someone indistinct
Converses at the door apart,
The nightingales are singing near
The Convent of the Sacred Heart,

And sang within the bloody wood
When Agamemnon cried aloud,
And let their liquid siftings fall
To stain the stiff dishonored shroud.

Answer 1

When Agamemnon cried aloud,
And let their liquid siftings fall
To stain the stiff dishonored shroud.



I guess "their" refers to the nightingales' "liquid siftings" that "fall" like droppings and spoil the king's grandeur and majesty. "stain" is a verb that connotes disapproval and "fall" suggests falling from grace or honor (suggesting death), "stiff dishonoured shroud" indeed has double meaning: suggests the royalty of kingship. . . . strict rules and conventions - morality but also mortality (death).
There's something sinister and spooky about "shroud". It is a kind of cloth that suggests death and disgrace/dishonor. It is itself shrouded in eerie secrecy, like the the cloth used to cover faces of the dead. . . . hiding from sight something, we want to view yet shrink away from.

Good luck