In reply to Kid Spatula:
I don't know the Cuillin well, but I was just there last week staying in the hut and did the round up the Dubh Ridge, across to Gars Bheinn, down it's SE ridge and back to the hut. (In glorious sunny weather, lucky sod.)
Would you be looking to head back down directly from the top of the Dubh Ridge, or to carry on around to Gars Bheinn anyway?
From the top of Sgurr Dubh Beag, or rather just after the abseil (or the retreat and traverse to avoid it), you could head back down Coir' a' Chaoruinn. After Sgurr Dubh Mor, Coire an Lochain probably is your best bet.
Trying to get down into An Garbh-Coire directly from either is probably a tad dodgy in any case without coming around to Bealach a Garbh-coire first. (My guidebook says "not recommended", and once you get around beyond the Bealach and look back it isn't hard to see why - rather steep and a tad loose by the looks.)
I think I must have got a bit lost, because the descent from Gars Bheinn was a wee bit hairy in places the way I did it. Steep scree, with a lot of false summits, and much that was boggy, soggy and slippy. I think I must have missed a turn towards the hut and carried on a bit too far directly down towards the sea - later on I stumbled across a narrow, slightly indistinct path traversing and descending the hill back towards the Mad Burn and the hut, marked with the odd cairn. Probably would have done well to spot it earlier.
You can see the whole route up the Dubh Ridge, around via Gars Bheinn and back from the summit of Sgurr na Stri. If you're staying at the hut, arrive with a bit of time to kill and have decent visability the views from the summit are well worth the effort to walk up there.