My wife has been 'fisting', hand fucking me for 30 years. Deep, nearly to the elbow. Sometimes without any lube on her hand when my ass was so wet and open from all the toys she fucked me with. So wet, just work the hand in and find the path.
One time when my ass was ready for her hand, she lubed it up and just rammed it into me. WOW!
Here's the proper protocol: Laying on your back, left hand, on your knees, right hand.
One time in one of those situations that occurred lying in bed, she put her right hand in me without lube while I was laying on my back.
I rotated my body to get on my knees while she had her hand inside me. That was fun!
Stroking and rotation of a hand deep in my ass produces amazing orgasms! I LOVE IT!!!!!