My DS went through a similar thing at around the same age. I was able to give him rusks, but actually found carrots a better alternative. I would give him a whole one, straight out of the fridge so it was nice and cool, peel it and then give it to him to gum/mouth. He loved it. It had a little bit of flavour and the cold sensation was a hit, but he wasn't ingesting anything. A lot of people told me I was crazy and that he would choke (the same one's who poopoo'ed BLS too), but I kept a close eye on him when he had one and he never managed to actually bite in to it or break it.

Also, I'm sure I've heard people talk about making their own rusks. Maybe do a quick google and see if you can find a dairy-free recipe...

HTH