"It's a ploy," he maintains stubbornly. Makes them himself with veritaserum, definitely.
Severus Ignores Albus (an Olympic-level sport) with all his might, and says with dignity, "I mention them only as a jumping-off point. In comparison to brownies, house-elves are giants," he holds up a hand at mid-thigh height. "They have no more interest in milk than anyone else, are, as a race, tiringly and sometimes bafflingly servile rather than capricious, although it's decidedly a bad idea to make an enemy of one. Their English is horrendous, and they all look as though they've been washed but then stuffed in a closet to moulder instead of being properly dried. Like brownies, however, they are exceptional housekeepers and will disappear if offered clothes--although I've had some success persuading this particular elf that clothing isn't necessarily the same thing as equipment or a uniform."