Well I may be the oddball but I do use some bottles for pee. But there is a reason, now I could be wrong in my theory so some of you may be able to correct me if you have more experience. But I take some workout supplements such has a multivitamin (turns my pee a bright yellow color the first two or three times after I take it), BCAA, protein powder, glucosamine, fish oil and vitamin D/calcium supplement. So my urine has a pretty strong smell and I am not sure if that would be the most natural smell or turn into an ammonia base like someone who didn't take workout supplements urine does. If I am wrong and there are others who are in the same boat let me know. It just means one less thing to carry in with me.