I do and have done for 3 seasons. Lovely pack very friendly. Some good jumping days but good for children too as the secretary normally takes them under a wing. Hot on manners and turnout make sure you're on your best behaviour!
Neue Schule do a starter bit which is meant to encourage horses to accept the contact. It promotes mouthing and acceptance and stretching towards the contact.
You can hire one first to try out.
http://www.dressagedeluxe.co.uk/Shop.asp?viewmode=vp&pid=985
Heard a lot of good things about them and a fair few horses like it. Its very soothing on their tongue and the bit curves up to leave room for it. I'm going to hire one from Dressage Deluxe as soon as I get paid!!
Have looked online and can't seem to find exactly what I'd like but I seem to remember seeing one last year.
Would like a fluorescent walker rug (with the cutaway shoulders) with reflective strips and tail flap for when I'm leading out for the horse being led.
Currently using an exercise...