Home-made Simulation
Here's a pretty good way to masturbate. First get a paper towel roll (adjust to desired size), then get a sock and soak it in warm water, squeeze it and get most of the water out. Place the sock in the paper towel roll. Then get a sandwich baggie to tape at the end of the paper towel roll to catch any mess/water. This technique can be done hands free or by using your hand. You may want to add some lube. Then just insert your penis and have it.