It might be fun to try some strongman type training. Big sacks of rice are probably more than available in SE Asia. Those would be good to throw around and put into wheelbarrows and stuff.
What about access to dumbells? So many options here. Single leg deadlifts, bulgarian split squats, weighted pistol squats. Go upper body crazy with rows, military presses, floor presses.
If all else fails try 'external loading via small cambodian children backsquats'. The load is unstable as they try escape, the loading parameters increase as they grow overtime - and one day it may be material for a best selling ghetto training manual. Its win-win.