Neat hand.
As it is, I am having trouble seeing how we are 'cold' at this juncture... unless we are lucky in the major suit layout.
We can't attack diamonds again unless we first unblock the spades... else rho wins the diamond and returns the suit.
So AQ spades.
Now we play a diamond to the 9: we do not play the Jack.
It doesn't matter which card we play if rho wins, since we then have 9 easy tricks, with red suit communication intact.
But if he ducks the J, we are left hoping rho has KJx in hearts or Kxx and fails to unblock the K under our Ace
While if we are in dummy on the second round of diamonds, we can cater to rho being 2=4=5=2, by cashing the spade King, which squeezes rho in the reds... he has to hold onto Kx of diamonds, so has to reduce to Kx or KJ in hearts.... while his partner holds a stiff at this juncture... rendering an ublock impossible.
So unblock the spade AQ, and a low diamond to the 9 wins whenever rho is 2=4=5=2 or is 3=3=5=2 with the KJx of hearts, or is 3=3=5=2 with Kxx in hearts and fails to unblock.
edit: I was writing this when the better line was posted.. I like the pitch of the diamond J on the spade K, and the line works against 2=4=5=2 shape as well, since east is squeezed on the spade King... of course, so does my line

In fact, I think my line stumbles into the same endgame

so long as one ducks when east 'unblocks' in the endgame, which I think would be easy to see at the table when holding only 4 cards.
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari