I have 1 muscovy drake to 3 hens. My drake doesn't cuddle. But, once in awhile I will scratch the front or underside of his neck, but only briefly.
He is about 6 months old. I have had the same issues. What has worked for me is that I hold him down with a firm hand on his back and a lighter hand at his neck. I don't push his face in the dirt, but hold his neck as it helps keep him calm. Sort of how he would hold down a female or another drake if needed. I usually just count to 60. I don't say anything while doing it, but when I let him go I say, "okay, now go on..." He generally leaves me alone after that.
When I first did it, he sometimes turned around to try to come at me again and I would do it again. Usually after two times, he would go on his way.
I don't act scared of him and I try to avert him if he looks like he might do something (bite my leg, pull at my pants, etc.) When I notice he might do something - I say "No" in a very gruff tone and clap my hands loudly.
I only hold him down if he bites at me or something else which seems aggressive.
After about a week or two of me holding him down, he has really settled down. He usually only does it while in his run not while out in the open yard.
One thing that I also noticed is that when I crouch down he doesn't bother me. Sometimes while in the run or the yard, I will crouch down to their level to look over them or whatever. I don't do this if he is being aggressive though.
So, I just always keep an eye on him, try to avert any behavior before it happens, and follow through if he does something. I noticed he usually bites at my shoe, pants, etc if I am going into the chicken area or as I am closing the door when I leave the run. I really try to keep an eye on him then so that I can prevent any aggressive behavior and then I don't have to discipline.
I think he really just wants my attention.
The girls will nibble me and him while I hold him down.

Also, I quit feeding from my hand and just throw his treats on the ground or put them in a dish.
I would try to observe your drake and see what his patterns are so that you can prevent rather than discipline his behavior.