i haven't tried this myself...no, honestly, but i've heard that using "water wings" to jerk off with, can be quite stimulating
you know, those inflatable "donut" shaped arm bands that kids wear in the pool...they're cheap, and provided that you blow them up enough, they should be a tight fit around your manhood
and i know this has been posted on the site before, but filling a baggie with lotion and putting it between the mattress and box springs and inserting your dick to fuck the baggie can also be quite stimulating...though if it's not stimulating, or tight enough, put your hand down on the mattress to create more pressure. you can also use a towel if you prefer dry friction to wetness
i've also used a banana skin to jerk off with before, and can recommend this device. cut both ends off of the banana, then make a single vertical cut down one side. carefully remove the banana, making sure not to rip the sleeve. then wrap the sleeve around your dick and enjoy. you can choose to add lube or not, but if the banana is ripe enough, the goo from the inside of the skin should be wet enough for your masturbation needs...plus, the more you jerk off with it, the slimier it becomes