Washing with snow?

I'd like to share something that I learned today, an idiomatic expression.

So, we've recently gotten more snow than I have ever seen in Lugoj, that is to say about 6 to 8 inches. It's been snowing the last few days pretty much non-stop, which, compared to last year, has been a virtual blizzard. And with all this snow, the kids have been understandably giddy. So have been some of the teachers (the ones who don't have to drive, I suppose). Walking to school has suddenly become quite perilous, not only because the ground is slippery and the snow is constantly flying in your face (regardless of which direction you're heading), but also because snowballs are darting in every direction, and it doesn't much matter who you are; if you get caught in their crossfire, you stand a very good chance of being hit.

Heading to school this morning, I noticed some children in a snowball fight. Luckily they were too busy targeting each other to notice me. One of the kids got in a good shot, whacking the back of another's head. The victim spun around in a fury, yelling "arghhh! te spăl eu!" This would litterally translate as "I'm going to wash you." "Huh?" I thought as I stared at them for a moment. Later, I figured out he essentially meant, "I'm gonna get you back!" However, at that moment, I was mildly confused to hear such an expression in that context. In any case, I didn't think too hard about it and continued on my way.

I had essentially forgotten the whole episode until I was suddenly reminded of it at school later in the day. It was Sima--the rascally mathematics teacher who always wears expensive suits--that reminded me. During one of the class breaks he had run outside to pick up some snow, and snuck back into the building with a few snowballs. Practically without warning, he pelted some of students who were close to him in the hallway. I quickly jumped for cover behind a movable billboard on which the results of a recent mathematics contest had been posted. The ambush ended when Sima ran out of snowballs. Deeming it safe, I came out of hiding. When Sima saw me, he said, "Oh Mike! Had you been here just a little earlier, I would have washed you." I could have guessed it, and I told him there was good reason I didn't want him to see me. What immediately struck me was that he had used the same turn of phrase as the children I'd seen on the sidewalk--his reference to 'washing' jumped right out at me. "What a funny way to refer to throwing a snowball," I thought. But, as far as I can gather from these two snow-throwing experiences, this is the standard way to describe the act of hurling a snowball at someone.