Being a male without much female interaction I find myself trying new and more exciting things. However, I believe I have stuck my manhood in every stickable object in my house except family members and pets.
My latest adventure during my alone time was when I was taking a bath in my big bathtub with jets. I thought it might feel good to stick my winky in the jets while the water came out. However I forgot that water from previous baths would still be in the jet line, and over night it had gotten cold. To sum up the story I stuck my dingaling in the jet and freezing cold water shot out. It completely ruined my plans and the mood with my bathtub was completely lost and I couldn't bring myself to try it again.
Soft foods are always a safe bet, though sometimes cleanup can be a bit of a pain. Another fun (and potentially dangerous if well endowed) one is filling a blender up with a fairly viscous fluid and hitting frappe. Just be careful not to go too far down.