Duncan, is that LHMO for both front and rear and clutch systems?Good advice from Beech. And obviously assume you've positioned the bike/bars in various positions to eliminate airlocks as much as possible - the slave cylinder looks to me like it could trap a little air. If still no luck it might be worth bleeding it very fast from top to bottom - that's all I ever do as (with a Mityvac and PTFE around the bleed nipple threads) but I have never drained it, so have no air in it. I never trusted the idea of draining it all out and pushing through from the bottom.
I use LHM (Light Hydraulic Mineral Oil - originally designed for Citroen DS suspension systems) as its exectly the right stuff and a lot cheaper than BMW, Magura, Shimano etc. Also saves £ if you have to flush a lot through to try to get air out.