Almost only slicing the backhand worked for Steffi Graf. If you decide to only hit slice, I would reccommend being able at least to either keep it low or float it deep. Most players will pick up that you only play it low and will be waiting for it before too long.
But as JT1 said - don't give up trying to learn a variation. Two handed, flat, topsin - one of them will surely feel right. Personally I would recommend the two handed because it compliments the slice the best - 1) the balls can be taken later so you have a solid stroke when you're late, and 2) the balls have good depth and topspin so it keeps the opponent off balance. On the other hand a lot of people say it's confusing to yourself as well, but I think you get a feel pretty quickly for which ball wants which shot.