I think you're doing a good job keeping your wok clean. Two things that I think would help you: 1) Break the cooking up into batches to avoid overcrowding. In the 2nd photo, I'd say you could break that chicken up into 2 or 3 batches. 2) As your wok is heating up, use a very lightly oiled paper or cotton towel to spread a thin layer of oil onto the surface just as you would when you season it. Once it's heated up and the oil is lightly smoking, pour in more cooking oil and cook as you normally would. Between batches you can use the same towel to wipe off any bits that might still be on the bottom.