I don't see what's so unbelievable about Solid's claim. 22kilos is about 48.5lbs. I don't know how tall he is so I can't compare his weight, but it looks as if he can do it for 6 reps.
After following the MAX-OT route for about a couple months now, I am currently doing 3x6 at 45lbs. Solid definitely has slightly bigger forearms than me and possibly slightly bigger biceps (couldn't tell in pic). I've been working out seriously for 1 year come September. I'm 5'11" and weigh a fluctuating 155-160 (maybe a little more now) and I have about 14% (maybe a little less now) bodyfat.
I also have used the wrist rollers and that is one of my favorite exercises. For those who haven't used one, it's like one of those cardboard pieces from paper towel rolls, with a hole it in attached to a rope to the floor and you add a weight to the end of the rope. Twist it up from the ground with arms perpendicular to the body then unwind it down. When I started, it was a strain at 5lbs, now I can go up and down once and sometimes twice at 25lbs. Amazing exercise.
It jumpstarted my barbell curls, explosively pumped up my forearms, and showed big increases after just about a month of using it. I only used it once a week and threw it in with my biceps + back day, but sometimes I threw it in again for a second time in the week. I don't see people use it often, but I completely recommend it either with or over wrist curls with dumbells or barbells.
