I tried another grass jelly like material called cool fruit. It is a can like grass jelly, but looked exactly like jello. This time I used a 3/4" wood drill bit to make a hole in the middle. The advantage of grass jelly like material can be seen in the drilling. The drill bit carves into the jelly like wood, making a well defined hole. I then wobble the drill bit at the top of the whole to make it a little large to custom fit.
The hole makes a lot of difference. I can insert easily with some force, a bit like inserting into pussy. The jelly will surround your cock and squeeze it. The best is you can pull out with very good stimulation. As you get harder you can exert more force and penetrate deeper into the smaller hole at the bottom of the can.
I had a good climate, with simulated penetration standing up with the can resting on the table edge. After a lot of abuse, the jelly didn't break, and the hole didn't even get any larger. Because the hole isn't too small, I can pull out easily with pulling out the jelly from the can.
So far this the best. I can mount the can on the table top for hand free operation. You can drain the can a little and most of the residue liquid will be gone. So there's not much mess but not exactly dry.
I made the full size fleshlight with potato starch. It was untended but I used the 1:5 mixture of starch and water. I made it in a plastic cup with 500 ml volume. I made the hole using the drill but it's like drilling into glue. The hole is not well defined because the starch clink onto the drill bit.
But anyway I can get in with a stiff cock. The penetration is OK. The squeezing sensation is OK. But you can really pull out because the starch is clinging onto your cock. Since you can pull out you can't charge. When I pull out I pull out the starch from the cup. It's really like the fleshlight in youtube. But you can't go up and down because of the stickiness. But the starch held together OK so I can squeeze my cock with both of my hands. I can move up and down a bit even the starch is all sticky.
It's a bit of wait for the center of the fleshlight to cool down after in the microwave. You need to bring the starch and water to boil to activate the starch. At the moment it's messier than grass jelly because the starch is not evenly cooked. The top fell off first. Then more pieces break away when I was exercising;.
Will try the 2:5 mixture to see if I can drill a nice hole in it.