Is it OK to use coffee or other drinks to clean road rash? This may seem like an odd question, but I was wondering if it's safe or a good idea to rinse road rash with iced coffee or other drinks? My usual strategy for road rash is to clean the fresh wound as soon as possible as thoroughly as possible, but normally I'd use water (and soap if available).

However, on my commute to work today I came across a fellow cyclist who'd just wiped out (biking fast around a wet corner, wheels slipped out from under him when he hit a slippery patch). He had some nasty road rash on his leg and elbow. He slid half on pavement, half on wet dirt, so the wound was pretty dirty. The only liquid I had with me on my commute is iced coffee (with milk and sugar). I offered him the  coffee to rinse his leg and he declined,  but he did use the packet of neosporin I gave him (which seemed of limited usefulness given how dirty the wound was). His bike was ok and he was able to ride on to work and said he'd have someone look at his leg later.

So anyway, I was wondering if cleaning a wound  immediately with coffee (or other drinks, like tea, Gatorade, Coke, etc) is a good idea or if it would be better to just wait until I get to home/work to clean it with soap and water? I'd do a thorough cleaning at home regardless, but is there any benefit to cleaning immediately after the crash even if I don't have any water available? Also, is the answer different if I'm facing a 2 or 3 hour walk to better facilities rather than a 20 - 30 minute ride?

And a related question, what else could I carry in my commute bag that would be useful for situations like this -- wet wipes? 

I did come across this related post on treating road rash, but it doesn't address what to do at the time of the accident: 

What do you do to cure road rash more quickly after a crash?
Plain black coffee would be okay; it's just water and it should be nearly sterile.  However, I would definitely avoid coffee that contains milk, sugar or other additives that can support bacteria growth.  

Now, this is going to come as a bit of a surprise, but what is an excellent wound cleanser is urine.  Yeah, yeah, I know.  But other than the ewwww factor, it's nearly perfect.  It's warm, sterile*, and near isotonic.  Naturally, the guy's not likely to agree to let you urinate on him, but he can do it himself.

*Assuming the person is healthy.