Take some of those boilies you made.....and put them in the microwave for 10 second incriments. Take them out and look at them. If they haven't started to scorch, put them back in for 10 seconds. Keep repeating them until they start to swell up. Now......drop one in a bowl of water
The only way to make a pop-up permanant is to use the pop-up ingredients, which are lighter flours. Some of those flours you need to special order, and you cannot get them under 50 lbs (Some of the Casseinates, etc.) and a 50 lb bag of that will set you back 250 bucks. Between Mishio and I, we have contacted at least 12 distributors, and they will NOT distribute under 50 lbs of that stuff. I cannot imagine what a 50lb bag of that stuff would look like, as it weighs absolutely nothing.
We've been pan rolling them, or microwaving them. Tried the oven bit, and it does work....but takes a little longer. Still, they do eventually take on water and sink. One thing you might want to try, especially if you are fishing packbaits, is getting some styrophoam balls from a craft store about the size of the boilies you are using. You can spray flavors on them, even coloring to match your boilies. The carp won't tell the difference.