I suggest anyone interested in doing a PC grow try doing a SCROG, screen of green, with chicken wire. the one plant this guy had, which looked to be a pretty good size for his lighting, could have produced as much as 4 times the amount with only a little more time spent vegging and training the plant. I know you say you don't care about yeild, but surely more is better if you dont need to spend more than a couple dollars and put in a tiny bit more time?
The only things you will need are: Chicken wire (enough to lie flat across your grow area), Duct tape (to install the wire), Twisty ties and/or string (to train your branches to the wire, and to train you top down at first.). Anyone probably already has some duct tape, so you need to buy a little chicken wire and some string or twisty ties (once again, if you dont already have this stuff).
A guy did a very good post along these lines a few pages ago, but I fear many may not have understood what he was trying to say. If you have this chicken wire installed at slightly lower than the point at which you wish to flower (for a PC box probably somewhere in the middle is fine). You use the string or the ties to bend the top so the plant almost makes the shape of an upside down "U". I believe this is called LSTing? I could be wrong. Anyway, the branches will start growing up to replace the upside down or sideways top, which the plant cannot seem to fix any other way. You then 'train' these branches to grow along the chicken wire screen. You can fill up the screen on the inside of a PC box easily with only one or two females (you would want to use feminized seeds, or start flower to show sex, then revert back to veg and just grow with the females). And with just a month of Vegging while LST'd, you could probably quadruple your yeild. Make sure its female before you start SCROGing though. It would be a pain if you SCROGed a plant only to have it go male on you. Sex your plants before you do this method, or use clones or feminized seeds.
Using this method can make a very large difference, even in such a small space. It allows you to literally make the most out of your small grow space. If you are gonna go the way of the PC box, you should at least consider this, It is accomplishable even by those with just a little bit of experience, and most of how to do it can be learned along the way. I know you don't care about yeilds, but others might, and I'm sure even the guy that started this thread would be happy if he tried it. It's also great for controlling how tall your plant will grow. Basically it allows you to grow the equivalent of a 2 or 3 foot plant in youir PC box. Just my 2 cents.