A standard serve of Carnation milk has about 40 calories, compared to hundreds of calories in a can of Ensure. They have thicker versions like "cooking milk", but you might as well just drink regular milk with some cream mixed in.
Sweetened Condensed Milk by Carnation or Pet is extremely high calories and cheap. Cheaper than heavy cream and nearly as fattening. If you are talking about that type of Canned Milk you have devised a wonderful weight gain plan.
Based on relative calorie counts it would probably be more cost effective to use Heavy Cream and chocolate milk. Drink a glass of that (mixed equal parts) with every meal and you'll be plumping up in no time.
Several women I know in the past 8 months have been able to drink it straight pretty easily. We discovered the benefits when one lady had a can around for baking and chugged it. The gaining results are fantastic if one can drink it. It's also a good mixer with a milk shake or a cake shake.
