S.B.
Sounds fun and messy! I have 4 kids, all of them did that. They're independent. Nonetheless, I strapped their hands down and taught them to keep their hands down while I was feeding them. Sometimes I would just hold their hands under the highchair if it was just the one hand. Then after I finished the messy foods I would put foods they are allowed to do on their own....cheerios, frozen peas, bits of banana....things they can practice on their own. Also, I would let them hold and play with plastic utensils during that time or just play time in the highchair. Occasionally I would let them hold a spoon and I would help to start them. My advice is to set boundaries now, they want to do everything on their own, but they will need help and it's good to learn that now.