I was going to leave this alone, but, seeing you want to make this an issue because of trees and your emotive desire to attach yourself to environmental responsibility...

I use recycled tissues. Light-as to carry, very effective in cleaning, and no trees were cut down specifically to make it.

Unlike cyccommute, who professes to be a keen angler and is very protective of his waterways, and you who just dumps your waste on to the ground, I try to avoid leaving food waste in rivers and lakes/rservoirs or on the ground because they are foreign to those environments, and in highly occupied campground, offensive. A significant amount of fat is deposited in one form or another in the "simple wash-up in the stream", and that is not good in any shape or form. Detergent... nah... more problems, even for those trees that you consider so sacrosanct.

I'll go futher. The beauty of using recycled paper in the form of towels or tissues is that it can be bundled up into a bag (plastic or otherwise) and taken out with you to a proper disposal bin. You know, the sort that park or municipal staff empty regularly and take to managed waste disposal sites.

I come from a part of the world that has strict rules on waste management in the not-insignificant areas of World Heritage rain forests. People who raft down the Franklin River, for instance, have to remove all their waste, including their own crap and urine... that is, it is a legal requirement that what they carry in, they must carry out.

I think the carry-in/carry-out policy is a good one to adopt even in the most basic forms.

I figure that rather than lambast my suggestions for using paper towels for your other favoured watery techniques, you think your environmental responsibilities through a little more thoroughly.

Next you'll be telling me that you toss banana skins at will "because they'll decomponse" when patently they don't very well; and that you can't camp without having a campfire to create "atmosphere and comfort and to cook". For what it's worth, again, if you light fires here right now, on total fire ban days, you might just spend time in jail. Fires have become passe in my camping experience.

And yes, Machka does do washing up -- generally when we are in structured camping areas, such as state parks where facilities such as camp kitchen are provided for such purposes. I know camp kitchens are a rare commodity in North America, but they are very common in Australian commercial campgrounds and again add that element of environmental responsiblity. And if push come to shove, I will use the campground toilet as the place to dump wsh-up material, not the ground.

Plus I, too, have used the sand/dirt technique, but less so these days because I used alcohol as my heating fuel, and its far more controlled heat means I haven't caught the bottom of a pot in a long long time. These days I don't bother washing the outside of my pots, either, but give them a quick wipe-over to remove the soot. The remaining ingrained black (my Trangia pots are mostly black on the outside) is an aid in reducing my alcohol usage marginally.