Improvement

In the school the last two days with Remy and his relaxation has improved with each session.  He's giving me the release and then maintaining it for longer periods, soft in the mouth and soft through the neck. I let him extend the neck a little, but ask him to keep his head up for  a short time and then give him a break to really stretch down. He still tests me to see that he can stretch down if he wants to, but this was much less today and he seems to be settling to it.
His reinback today felt very calm and well balanced and because he was more relaxed, he really seemed to come together and he gave me bigger steps. We tried some reinback to trot transitions into a pretty manageable trot, which is a big deal for us and then shoulder-in on each rein! I'm so excited by this, I really think we're starting to get it. I rode him home down the lane and he felt as light as a feather, his whole body underneath me.

I've got him some hoof boots - Boa's,  not my first choice it has to be said, but the only ones that would give a good fit. I tried them today and they seem ok, didn't seem to bother him, in fact he seemed to be picking his feet up much better. I've got them for his hind feet as he's lazy and my sand school is very abrasive. He doesn't need them when we're hacking out so I'll only use them in the school. I was worried about the sand getting inside them, but they come complete with neoprene gaiters which seemed to work a treat. Anyway, we'll see how they go.

Release

I've been thinking about this for the last few days.
When I'm riding Remy I ask him to release all the time. I want him to relax his jaw, give his mouth and also relax totally through this neck, in other words to make himself completely vulnerable. Well, he doesn't do it.  It's a big ask, so obviously, he has to be sure that I'm not going to abuse this most wonderful of gifts.
He relaxes his jaw when I ask from a lift to the corners of this mouth. I never pull back (try very hard never to pull back). As soon as he gives his mouth, I release the contact and allow him to extend his neck, or at least I thought I was doing this, but I realise I'm not doing it sufficiently/enough/correctly, whatever word fits the bill. What we have is a compromise - intermittent relaxation of the jaw, intermittent relaxation of the neck, but not a true, genuine 'giving'.
It's my fault, I'm slow to catch on, but over the last few days, I think I'm finally getting it. Hallelujah, says Remy!
I started in the stable a few days ago on a very wet, not fit for riding day. I took the bridle in and we did a few flexions. I stood at the girth and gently asked him to flex, then immediately gave and allowed him to stretch down. He started rather tentatively - he has this habit of flicking his lips when he's bothered by something - but as he realised that once he'd relaxed his jaw he could stretch down as much as he liked he started to relax and he became lighter and lighter, the muscles in his neck started to relax until they were lovely and soft and I could feel that he had really 'given'.  Giving, without holding through his neck is a big thing for him and I need to assure him that he can do it and he's going to be ok.
The day after, I took him to the school and we did the same thing on the ground and then a few flexions mounted, allowing him to stretch immediately he relaxed his jaw. He really tested me on this, just making sure that he was free to stretch, but gradually we had the same soft, relaxed feeling I'd had on the ground. We left it there as it was a horribly blustery day and I was proud of the way he focussed on me when there were so many things to distract him.
Today, back in the school, same thing, and Remy at first really testing me,  again making sure that he had the freedom to stretch, but gradually relaxing and settling, with a lovely soft feeling in the hand. I gave him lots of breaks to stretch, but inbetween there were moments that I find difficult to put into words, where he was in balance, motivated and the feeling in my hand was like holding air, a tangible energy and a delicate balancing act to try not to lose it. This training lark is so difficult and there are many things I don't know, but I know that for a few brief moments today, we were together!

The penny drops..........

.....for me, that is. I had time for a short session in the stable with Anky this morning, but had to wait until this evening to take her up to the school.
We started in-hand, asking for the release and the stretch down, slight flexion inside and then transition to walk. 
 We were suddenly doing it, our first (albeit very basic) tension free, relaxed work in-hand. A light vibration on the inside rein to ask for the flexion and as she released, she also took the rein down. The more we did, the more she seemed to want to stretch. I felt a real connection, I imagined her sigh of relief that mum had finally 'got it'.
Of course, it was there all the time, I just had to find it.  It's a start.