Preparation: what can one do?

I have posted a similar, but more specific, question in the German forum because the question is relevant to my German learning, but I also think it might make for an interesting discussion here.

I am going to be paintballing on Saturday with a group of Austrians near Vienna. I am pretty certain that I will not understand the vast majority of what they say to each other and I am not worried about that, since I know them, and they won’t be expecting me understand. I look forward to seeing how well I understand in such a situation. However, I naturally want to do whatever I can in the next few days to give myself as much of an advantage as possible. For this, I currently plan to read a large number of texts on paintballing in LingQ and watch as many videos as possible on the subject. If I can find any audio, I will listen to that too.

My question is this: what can somebody do in such a situation, in such a short time to prepare? When somebody knows that they will be in a very specific situation that requires a very specific vocabulary, can they, in a few days, make a significant difference in their ability to understand and speak? Also, what kind of experiences have people got with doing this kind of thing?