I've tamed kittens a bit older than that, they were being fed a what-ever-their-momma-could-catch diet lol. I used canned food to bring them around, as long as you use a grain free canned and just use it for practice you should be good. The baby food is ok too...
TBH what I'd use though is chicken hearts. They seem to be raw fed kitty candy. My cats gobble them up like there's no tomorrow, lol.
As far as the towel method...I didn't read it, but I would try this:
Put on gloves. Scruff one of the kittens, then move it to your lap (or the floor right in front of you if they're doing their best chainsaw impression). Use your other hand to pet and scratch the kitten gently, speak to it in a calm voice. Rub it's head and neck, good scratches will help. Ideally you're aiming for purring, but in the beginning just relaxing a bit is good enough. Once the kitten has relaxed you can let go and they can choose to move away, or they may stay for more loves.
Repeat with the second kitten.
If you do that once a day, or twice is better, you'll see big changes quickly. They need to learn ASAP that people are nice and pets are great. At this age they're very forgiving, so you can use gentle force (scruffing, but otherwise treating them gently) to help them come around.
You'll fine that after a few days you probably won't need to scruff them, a hand on their neck will do, and you'll start getting purrs pretty quickly. After that they'll relax, maybe even fall asleep on you. The kitten I caught were 12 weeks old, and it took me a week to get some of them napping on me. I'd bet your boy will be like that.
The little female may take a bit longer, but between the food, cuddling, and add in some play time (ideally something where you hold fairly still) they'll be happy to see you in no time. Laser pointers are perfect play for these kittens, you can hold still and move only your hand and they'll forget you're even there.
Now we need pics!!!