How should you squat over hole in train over in asia?

Clothes to ankles. To avoid soiling them and allow knees to spread apart. Hold onto handles, especially if train is moving. Excellent hand washing facilities in first class trains, especially japan. Take your own supply of toilet paper in countries or trains where it may be lacking. Carry a supply of alcohol/lanolin based hand sterilizer. Squatting for eliminations is both normal & physiologically healthy.
Agree w Dr. Klauber. Spent part of my childhood in Asian where the "benjo" consisted of squatting on the side of the road or into a ditch. Toilets can be hard to come by. Use similar to a trench latrine.