You should just razor the neck area and keep it trimmed short if it’s thick. Don’t use any products. The products can make itching worse.
But if you really want to thin it out and slow the growth, I used to be like you, and chemo has done wonders for that. Slows all the hair actually. (/S)
But seriously it’s curious not having a fast growing beard. Haven’t known what that’s like since I first grew one at 12.
The cocktail starfish