It can take time but it ends up worth it. It took me two years with Celeborn and two with Thorn but they wound up being the biggest mushbuckets.
I had to intervene several times when they got into spats with the others while the process was going on but it still happened. It can be done but takes patience. Just a matter of how badly you want it. I WANTED to hug and kiss those big, bad boys. LOL
I would love to pet and love on him. You can just tell he hungers for it but is so scared to let anyone get close. I’m guessing he’s been chased away from many doorways. :(