I think we spoke about this recently. I climbed Chrulaiste from the west on my way to Kingshouse, and this apparently is the less-boggy way up. I know you asked about climbing from the east but from the west isn't really much of a detour from the WHW. If walking from Kingshouse, a few hundred yards before where the WHW heads up the Devil's Staircase there's a gate on your right. If you go through this a faint, muddy path can be picked up heading NNW for a time, following the fence northwards around the hill's western flank. It starts to peter out quite quickly, thereafter only existing as an occasional trace. When this happens it's probably best just to pick your own way up, as directly or indirectly as you want. It's wet in places, but wasn't too horrible when I did it (although this was after a week of sun). I'd suggest aiming to the left of any rocky outcrops you see above you, as this should bring you out onto a flattening with some peat hags and a fairly good path which leads straight to the summit. Bog dodging is straightforward during this part and the climb becomes rather more enjoyable. The summit view is outstanding in every direction. Buichaille Etive Mor is the obvious draw, but northwards the Mamores, Grey Corries and Ben Nevis look gorgeous (and give you an idea how far you have still to go on the WHW), and eastwards Rannoch Moor stretches out for miles. It's totally worth the steep climb at the start, and you could be up and down in a couple of hours, leaving plenty of time for the relatively short stage to Kinlochleven.
As for the Devil's Kitchen, it's just a path that winds up the hillside - not especially steep, not deserving of the intimidating name. And when you do stop for breathers on the way up you have the Buichaille to admire. I was coming down this path, but going up I'd imagine would only take forty minutes or so. And at the top, your route for the rest of the day is mostly gentle, passes a couple of good water sources and gives really, really lovely views of the Mamores, which you'll barely have to turn your head to view. The final descent to Kinlochleven is a bit dull, but by then your mind will probably be on tea.
I hope this helps.
