Aye know these paths well as I inspect them as part of my work .
The terrain off route here is as steep as you'll find and deadly slippy as you say , best to take compass bearing to keep out of harms way
The descents are fairly clear at Bealach Bheinn a Bheither and to the seaward (west) ridge of Sgurr Dhonuill ,drops you back onto the horseshoe road.
Another more difficult route is off in the coire between Meall a Caolais and Bheinn Bhan which drops you down a faint path to St Johns.
If you do end up in the wood , a working commercial forest .... aye can be a nightmare