I'm currently hired on a temporary basis at a company to help out with some low-level integration with certain IM services. Their current programmers are all C# programmers relying heavily on that framework, without a lot of knowledge about low-level concepts like the Win32 API, pointers, assembly, and the likes. They hired me because I've already done a few freeware projects that involved the kind of integration they need.
The current problem is that I'd never planned on working here for a long time (just a break from my current CS study), but they have a lot of projects they want me involved in. Too much projects for me to cope with in the month I have left on my contract.
My boss is quite a reasonable person and is trying to help me out by attempting to do some of those projects, but in the end this just backfires as he's constantly asking me for help, I end up holding his hand through the entire project, and it ends up costing me even more time. Paired with other problems like a language barrier (their native language is not english), this is a real annoyance, and I'm unsure how to cope with it.
I asked earlier "How to deal with someone else completely ruining a project?" on this same subject, but after some of the answers there (and a walk outside to calm down) made me realise that this is neither the problem nor a real solution, and the best way to go would be to just tell them. However...
How do I subtly tell them, and my boss in particular, that their help is appreciated but only slowing me down, and that "just teaching" them all of this is not an option[1] ? I've been trying to put my feelings in an e-mail towards them, but everytime it ends up being much too complex in language (e.g. they might not even understand what I'm saying), or way too blunt.
[1] Teaching them would involve explaining most of the low-level workings of a computer, and have them practice a LOT of reversing. Given that currently they have no clue what a pointer is, have never done their own memory management, and keep refering to my code as "Black Magic", I'm really not up for the task of educating them.
EDIT: Don't get me wrong, I love to teach people things, but given that I'm currently swamped with work, I'm really not up for taking someone completely from basic C# knowledge to low-level C, Assembler, and Reverse engineering skills. That stuff took me several years to learn for myself, and several more to practice enough to become good enough at.