I understand cash-tight, I have been too poor to own a car several times. I think you already understand the ramifications, but in case someone else trips over this:
You may have some success with the products. I suspect you will have to use them more than a few times, and each time, you are going to compromise the cooling system a little bit more. Over the course of months, this turns from a bad head to a vehicle that is not worth saving later. In any case, I would not drive this car out of town at least out of affordable towing range.
Incidently, there was an interesting Mythbuster several years ago that dealt with products and myths for stopping a radiator leak. An egg ended up being the most effective, if I recall. Does that mean it works on head gasket? I have no idea. I might try it.
I don't know how the car dealers/junkyards are where you are. Here, there are plenty of small used dealers with 10-20 cars, and if it were me, here, I might just drive it down, disclose the leak, and see if they have anything with 4 wheels that will be reliable transportation that they would do on a straight trade. If you could do that, then you still may have a viable vehicle in 6 months. I don't think the X is going to make it that long if you poor Kryptonite in it. Besides, if you part it out, you have the hassle of finding actual buyers, shipping, and all that wonder.
This is just commentary, I think you want to try some chemistry, and I'm fine with that. Best of Luck!!!
Edit: I guess you could part it out after the chemistry finally fails, assuming it works at all, there may be sense in doing it that way.
Edit Edit: What do you absolutely have to have to make a repair? If it is a head gasket, then is it really much more expensive than the chemistry? You may be closer than you think to fixing this, not perfectly, but runnable?
