Yes you can use milk to line his stomach , but a full stomach works better. But i can be used as a last resort.
If he needs his medication every 12 hours then offer him a measured amount of food every 12 hours. Try to get him into a routine even if its a full stomach of fresh chicken. (it is low in fat aswell) This will make it easier for you to administer.
Please bear in mid that if Max has not had milk in the past regulally then it may upset his gastronintestinal system.
If he has had milk on a regular basis in the past the guts work up a acceptance of it, less likley to cause a gastrointestinal upset such as dirrohea or vomiting. And milk does contain fats , adding to his weight problem.
Please express your concerns to your veterinary surgeon, It can be difficult to stablise seizuring activity in dogs, are all the tests normal that max has had done? If the tests are all fine then seizuring in dogs can be classed as Idiopathic - this term is unkown seizuiring, but getting the dose of the tablets just right can be a lengthy process to combat the seizuring.