The REAL Shimano bleed kit has a clamp that goes over the hose, over the bleed nipple. I guess I have spent too much time racing cars and working on automobile brakes to think the bleed nipple is bad.
You can also take the brake caliper off of the frame, let it hang and gravity bleed the Shimanos. Use the funnel on the lever and call it a day.
I am not sure what could be easier than gravity bleeding brakes.... you literally only open the bleed nipple at the caliper.
The long black thing near the end of the hose is the clamp that locks the hose on the nipple. If you are still bowing it off, you are pushing WAY too hard on the plunger. I suggest you gravity bleed instead if you have gorilla hands.
And this is the bleed kit you should be using, not the cheap one without the funnel: