I have very soft hands, so much so that it's sometimes difficult for me to ride horses with harder mouths because I cannot adjust. When I first rode Harper, it was in a small ring with a halter and leadrope, and I noticed how she was very sensitive to my hands. I didn't think much of it and decided I would wait until I had a bit in her mouth to decide how soft her mouth actually was. I have been warned by person after person that her mouth will be ruined, I may never get her back to normal because of her original training and she could probably never be used as a dressage horse and would always have issues because of it.
As in most things, Harper laughs at convential wisdom. I put her in the softest bit I have (loose ring hollow mouth french link snaffle, *phew* mouthful), got up on her, and started her on a straight line. The second I went to take a little bit of slack out of the reins (I had dropped them to get some of her mane out from under her saddle pad), she stopped. I figured I had done something odd, so I got my reins right and asked her to keep on. She seemed completely confused, then backed up until I put a lot of slack into the reins. Every time I didn't have a ton of slack in the reins while going on a line she did this.
After fighting with that, I thought maybe she had a pretty soft mouth. As I went from dressage-mode to trail rider-mode, I opened up my right rein but only managed to move my hand a few inches before she took a very sharp circle. I was totally not expecting this as I asked for a wide one, so I overbalanced a bit and pulled both, she stopped fast enough to nearly throw me over her neck. We worked for another 45 minutes, and she didn't get much better.
In that time, I discovered that her sides don't even register a kick or a squeeze. The only time they seem to wake up is when I squeeze or kick and cluck at the same time, then she reacts like I've hit her with spurs (she had very abusive former owners) and launches forward 10 feet before settling into a walk. Clucking by itself doesn't do this, and squeezing/kicking does nothing at all.
How do I even go about starting to normalize her? I have never seen a horse with this soft a mouth. I tried my bitless on her and she hated it, she does great in a halter but it's hard to stop her in that. Also, any tips on working with the cluck/squeeze thing?