I went to the vet. It turns out they were still scabs, and not discharge! She ended up having to use a scalpel and picking off the brown stuff to figure out what was underneath, and it was just white flesh. Not infected or anything. Which is how she figured out that it was just scabs. The vet said it is probably irritation due to something in his environment, and she guessed it was the type of aspen I use. She recommended shredded aspen, which is softer...
But in terms of husbandry, she actually did not know much about snakes ahah. :s All in all, she basically thought that heat mats will frequently malfunction and burn snakes (did not know about thermostats and their use) so recommended I use an infrared heating bulb, and did not know that snakes have eye caps (said that Yukon doesn't have eye caps).