I built a taming pen (3x3 with stone fence foundation and on top of that 2 high with stone door frames) then I took the Mantis and dropped it in the pen and landed a bit away, used bug repellent and cactus broth and feed it when it stand still. If it get agroed at you simply leave the area for maybe 2-3 mins and you should be good to go!
Best method I was told. Build a 2x2 stone [or wood if low] foundation with 2 high walls, drop in with flyer, feed through wall. Has a massive hitbox to feed it through if lured close to a wall. No repel needed with this method.