The top vegan egg replacements for breading are aquafaba (the brine from a chickpea can), and plant milk. However, anything wet that sticks to the breading does the trick. A thin layer of a bit of watery mustard or vegan mayo does the trick as well. Another way is mixing non-dairy milk with some ground flaxseed, aquafaba, or vegan mayo. Our schnitzel recipe uses aquafaba, as it is the most neutral tasting one.