I made a home made version using clingfilm and tinfoil. I filled the thing with water, making sure there wasn’t much leakage and put it in the freezer for a few hours. Out came an ice version of my penis which was quite neat because I could look at it from perspectives that naturally isn’t possible otherwise. Gives you an idea of what your size actually looks like and if you put it in your mouth you can have a first hand experience of blowing yourself which in my case actually helped some with size anxiety.
You could also fill the thing with lemonade and have your own penis popsicle.