If you are having trouble bleeding your clutch fluid then you need to read this post.
If you have managed to get some brake fluid through but the clutch pedal is now going to the floor you may have emptied the fluid reservoir. Ah! you say, I've just checked that and there is plenty of fluid in there.
Go and look again. But this time look closely at the back right. You will a small pipe coming out at the bottom. This is what feeds the clutch slave cylinder. Now look immediately above there and you see that the reservoir actually has a separate compartment in it just for the clutch and this may be empty!
The brake fluid can be at maximum and this section could still be empty.
In the two photos attached, I've circled the empty section and the blue arrow points to the pipe feeding the clutch. As you can see, there is plenty of brake fluid in there but none getting to the clutch.
The only way to get fluid back into here is either bleed the clutch backwards, pushing fluid back into the reservoir (the is how VX do it) or, as I've just found out, top up the reservoir to ABOVE the maximum level. Once you get past the max level you should suddenly see some air bubbles and the level drop and the clutch compartment fill up.
Most people on here use a Gunson Eezibleed kit for bleeding the clutch and this works because it keeps a very high level of fluid in and pushes it through.
However I was using a MityVac Vacuum bleeder which sucks the fluid out.
I hope this post is useful to someone else as it would have saved me several hours if I had know about the clutch section.