What the disadvantaged use. XD haha, so I haven't asked to buy an STP yet (I can live without for the time being) thus I use medicine spoon.   When I first saw the idea, people were saying to cut off the end of it and there you go!  That's what I did and it worked, although it was a little rough around the edges.  Occasionally, there'd be the problem of the flow being to fast or something and it would spray weird.
Anyhoo~ when I was out with a couple friends and S.O. at the beach one night...I dropped it and didn't know XD  Tis gone forever to be a mysterious plaything for small children.  The horror.
I got another though, but this time, mah boyfriend really wanted to help make it into a urinary device XD  but instead of sawing off the end, he took this small sharp tool (forget what it is) and drilled/carved a perfect hole in the center... And it works AMAZINGLY.  I was so excited XD  It prevents any flow/splash problems, looks nice, and even adds that extra splash at the end when you empty the rest out that got held in there.   So yeah, wanted to share that in case any o you guys found this useful.

I had the same problem when I first made one.I never used it in public really,at peoples houses and mine.Took me a ton of practice god.ill never forget that.ill have to try the drilling a hole in it next time :]