Ghost kit is way more trouble then its worth. If you plan on using one, leave it behind, and if you are in BMQ with a ghost kit, throw it out. If you have a ghost kit and the instructor asks Are you using this your shaving kit and you lie, they WILL find out and you will cause ALOT of problems for you and your section and even platoon. I just did my BMQ/SQ last summer and no matter what you think its everything is important and part of the experience.
You go to training to learn to do a job, not to learn to cut corners, from my minimal experience in the army, everything they teach you in BMQ/SQ is worth something and there is a reason for it, cant speak about the rest as I haven't done anything else...
Besides the instructors know most of the tricks, if a recruit thought of it, the instructor likely knows it...