Only one at a time should be used
as many as you want.
Once.
You can use each lightening bolt only once, but you can use as many bolts on one howrse as you like.
once
once
once
Once.
Unless otherwise stated, once and once only.
Once. That's why the package says "use once and destroy". See if your city has a needle exchange program.
Once then you put it back
Never once
Nope you can use them as many times as you like (: