Here's how I tamed a 145 Carcha. Traps do work you just need to make sure it has enough space to move around. I recommend just feeding it a baby rex as it will fill the trust bar to 100 (higher levels may need 2) once it trust you just feed it some sacrifice tames. I would also recommend rexes for this but anything which you can get high health on should work fine. I just leveled them up till they had like 60k health and I only had to kill 2 to instantly tame (1 would probably been enough but I think both died at the same time). My rates were 5x but this should still work perfectly fine on lower rates. Hope this helps and go tame yourself a high level carcha!