I have heard people complain that egg wash on chicken makes the coating harder. I use egg wash and cracker crumbs for oysters but they aren't in the hot oil as long as a piece of chicken and cracker meal is different than plain flour. For fried chicken, which I get too little of lately, I like to soak my pieces in buttermilk that I have seasoned. It seems to soak into the chicken giving more flavor and the acid will tenderize the meat, not that chicken needs tenderizing. You could use buttermilk for shrimp, fish, rabbit, squirrel or cutlets. You can also use plain milk or better yet evaporated milk that you have seasoned. Try adding mustard to the milk, try adding mustard to the egg wash as well. I guess my advice would be to try both ways and decide for yourself which you like better and which is less trouble.
On shrimp and fish I usually coat with yellow mustard then dredge in my super secret fish meal which is 2 parts flour, 1 part corn flour, corn starch, black & red seasoning, bit of onion powder and paprika.