Well, as you wish, but let's make a game of it. The one who got the right answer gets a point, and can say to which sherlock character the point shall go, the character with the most points wins!
Here's the riddle: I have a head but no arms. I have a tail but no legs. I am not alive, but I help people live. What am I?

Ha…. I figured someone would have heard it before!   
Yours is a coin, right?   

Ah!  Pressure!!      . . . . . Sherlock.   
How about - "What asks, but never answers?"

Question mark?

Sorry, I was at work!  I found that riddle online, and yes!  An owl!    Whoo-woo!
But I don't think the author considered your other answers… they win too, in my book! 
(and Mattlocked, you fondly reminded me of that hilarious game, I believed popularized/often used by the improv show Who's Line Is It Anyway, where you can speak in nothing but questions)

Yes maybe, I didn't put it there because it wasn't really sherlock related in the beginning! Should I change it??

Tooth?

Cheers...do I have to think of one?(That's why I don't play these games!)
Ok.
This is a bit obscure, so shout at me if need be!
I am plastic, with a slot and can be punched or thick.
What am I?

Well I tried, but it's a bit rubbish...feel free to post an alternative!

No, but you're in thr right department...so to speak!