Not sure what to do with my horse?

Loosen the bridle so there's at most one wrinkle, and not a big one at that. Ride him that way for a few days, and see how he does - this may stop the grinding.

The 2-3 wrinkles method is relatively new, and lots of horses don't respond well to it. It's just too tight for their lips. I've ridden for 50 years, and until the last few years everyone recommended only one wrinkle - or even no wrinkles.

Tighten your cavesson as much as possible.

If that doesn't work, then I might try a flash - with the looser bridle.

Three wrinkles, really? Who recommends that anymore? I thought all that was old, tired and dead. Way, way too much pressure on the mouth. No wrinkles is a better way to go. Also, it sounds like you change bits often, which is also not good in my opinion. Try an oval mouth that is nice and soft but understand, this could be a longterm habit with this horse and he may never stop. What you should NOT do is to bind him up in a flash or cavesson. These are horrible instruments of torture and you should train your horse to a behavior not try to tie him into it. I've seen horses with these things so tight there was blood pooling in the tissue around the mouth. The poor horses' lips looked engorged and swollen, just horrible. So stay away from the extremes and once you are trying something new, utilize it long enough to see if it can be successful. I had an OTTB (and they all have busy mouths from the track) and I rode him bitless and he was happy and content and performed beautifully. He hated any and all bits and would just chew, chew and be mouthy no matter what. Some never get away from the behavior once it is so ingrained. The bitless alternative sounds right to me here. best of luck. Just think about putting your horse's best interest FIRST and you will be OK and, best of all, so will your horse.

3 wrinkles on any snaffle? How bout you just reef the h%ell out of him with your hands?

You have a few good suggestions so far. Some horses do well with a lifesaver or roller mouth. But if you never give slack and GET OUT of their mouth's they all play with bits and act goofy

I COULD see why a guy with really soft hands takes 3 wrinkles. The horse is very soft and at a point where he cues lightly. However... that being said, when we get a horse that light and want to go lighter.. the mouth section gets thinner or we start into curbs and the hands get "telepathic". Good bitting always starts mild... has lots of "release" and as the horse lightens we end up with bits that allow neck reins and depend on legs more than shanks and mouths

Do try dropping the bit as suggested.

Also try: straight bar copper or rubber, bosal, English bitless hackamore bridle.

What happens if you ride him on the longe, without a bit, a trusted assistant working the longe? Does he just go, or does he fuss even then?

Try a copper roller or a sweet iron bit. Both promote salivation. My mare played with the bit relentlessly when she was young, until I got a copper roller. I now use a sweet iron bit on her.

YOU SHOULD USE A HACKAMORE (bitless bridle) horses will more than likely respond better to them than bits. and You wouldnt like having metal in ur mouth, would ya! but if u do, get a fleece hackamore. Never get a bosal!!!!!!!!!

The trainer told you that two or three wrinkles from the bit was GOOD? Get a second, third, and fourth opinion.

what about to let the bit done a hole on one side to give one or two wrinkles in the corners of the mouth? I might try that...

Bitless :)