I've had a beard or goatee since I turned 16 and now I'm a few trips around the sun past 50. My beard and head don't seem any different to me, and I've always just shampoo'd and conditioned it all the same. Unless it affects my sanity, I've not noticed any I'll affects.
I'm not sure what beard oil or any of that stuff could do for me. I do have to crop it occasionally, as it curls in weird ways after it gets over a couple of inches. But, if I have to put oil on my face to prevent the curling, I'd just assume crop it as I've always done.
I did shave once, when my daughters were young, and they cried every time they saw me till it grew back, as did every one else, ha ha!
I do get told that I look much younger than I am, of which I'm grateful, even if it is a damned lie. These days, I treasure the lie, and avoid mirrors, ha ha