Well the slice backhand is not really that valid to talk about because there are many two hand backhand players that use one handed slices.
Goodia are you new at the game? Because on my high school team, there are a few players that I'm trying to teach, since our good coach left us
. They have these one hand backhands which are horrid, as if they are playing racketball or something; they swing their racket down inconsistently doing some partial slice and then they complain about people who hit the ball too high or just get the ball back. So instead of trying to teach them a regular topspin one handed backhand and hoping that they won't have bad habits and revert to their old ways, I'm trying to teach them two handed backhands to start from scratch.
However my efforts are useless as they claim that they are comfortable with their backhands and insist that they can become great players with it. And then when I ask them if they have seen any professional, or even any top junior hit like that, they tell me that this is the way they want to hit.
Ugh sorry for the post actually, my frustration with these youngins is stressing me out. But I know for a fact that one of these freshmen will turn out to be an amazing player.
Well, you are their coach so it's up to you, but I think if they are comfortable with their style and having a good time playing you should let them carry on as they are rather than remoulding their games. Many professionals past and present don't have a cast-iron perfect technique for some of their best shots, yet they are effective with it through years and years of practice.
Don't sweat it if they're struggling with their one-handers. Not many kids around still use it so I think we should embrace those that try.