Well, I've been in Lech (
) and let me tell you first hand that the rulz were that you did indeed bring out all solid waste.
The problem was with more liquid waste, and l there is a lot of it. It's difficult to handle because there is an equation to balance: If you bring out pi55, then you will have many more traverses for a given length of exploration, because more trips will be to just carry it out. Lech is VERY hot, and you drink a lot of fluid, otherwise dehydration sets in fast.
So how do you balance more trips vs. bringing liquid waste out..tricky, and more complex than just "bring it all out"....
It took us 27 hours to reach our camp site in the Far East, if we brought out liquids from there you simply could not carry the liquid you emitted to get to that point. This is as remote a place as you can think of.....
On the flip side of this were some crazy policies by the Park Board (such as closing some of the camp sites) resulting in 12 hour round trips to reach pushing points, and thus damaging the cave by doing 13 hours of caving for 1 hour of surveying. This slows exploration and results in a lot more footfall than is needed.
On a side issue, I can claim to have introduced the concept of cling film for number 2's. Sheet of cling film on the ground, do the biz on it, wrap it and put it in your poly bag. Much better than balancing trying to cr*p directly into a ziplock bag. DO NOT OVERBALANCE