does anyone have experience using a dog bone snaffle?

Crystal Asked: does anyone have experience using a dog bone snaffle?

I'm going to be getting an ottb in two weeks and I think I need to change the bit that he currently uses.
A little background. The horse I am getting is about 10 yrs old and did race in Ireland. I met him when my mom wanted to start taking lessons. I found a place and lessons began. He is very bomb proof when in comes to New things and has never spooked. His problem is that he is a little pushy, I think because he never actually gets any ground work, people just show up for lessons get on and go. I have ridden him a handful of times and besides the fact that when I get him I need to teach him leg cues I will be doing ground work as well. My thought is with ground work he may not need a different bit (he currently rides in a smooth snaffle) he responds but not well. He's perfect for my mom (who will continue riding him as well) however for someone like myself who has much more experience he is kinda slow to respond. So I was thinking while training in arena to put him in a dog bone snaffle for a little extra bite, however I have never used this type of bit and don't know how harsh it is? I don't want harsh, I just want him to realize that when asked he needs to do! Lol additionally when not training I would like to keep him in a snaffle as long as he learns to respond better.
Any thoughts? Different ideas on bits to use during training? (nothing very harsh)

Also this guy has a few hundred pounds to gain before I can do any true training (yeah, the lesson woman really wasn't feeding enough, hence why I'm paying $2000 for a horse worth nothing near that, but I want him in a better environment as he brings my mom great joy and deserves it)