I could never ever EVER imagine my ASD DS eating with cutlery- he was so accomplished at eating with his hands, plus i thought it would be too hard for him coordination-wise and oh yes, he's never been particularly motivated by food (well not meals at any rate). But (and I can still hardly believe it) our ABA consultant cracked the problem within a few days, to the point where, if he was spooning cheerios into his mouth and dropped some on the table, he would pick them up and put them back in the bowl so he could use the spoon.
It really was just a case of being persistent and breaking the eating with fingers habit, sadly there was no magic wand! And there was relatively little protest from him, as a) he realised we weren't going to back down and b) despite not being a massive eater, it dawned on him that he could eat much more efficiently with a spoon. I had worried it was a bit cruel as he was so happy eating without cutlery but he is a lot happier now and it does look a hell of a lot better when we are out anywhere.
I can't remember every stage of the process but it
started with us doing hand over hand, and praising even that v highly. Then we would fade back our help, so starting him off and then letting go, or letting him start and then helping him bring it to his mouth. AND this was the biggie...not letting him pick the food up with his fingers, just blocking that completely. It's like potty training, you can't really give mixed messages.
We did also set up the laptop on the dining table for a bit and put a fave programme of his on iplayer, pausing it until he made some attempt to use the spoon and then playing when he did so.
Like I said, my non verbal son with his floppy fingers and awful co-ordination, plus incredibly stubborn nature...I could never see it happening. But once the penny dropped for him it was a breeze, and he would never dream of reaching for food with his hands (except the appropriate ones iyswim). Perseverance is the key, and belief that it can be done.
HTH