I'm assuming, in this case, that you mean one-shot items, instead of, say, armor.
I can think of two approaches.
Let's say that only members of the Oi! Punk class can use Broken Bottles as one-shot damage items. You could create a skill, "Throw Broken Bottle," that only Oi! Punks have. This skill would, in turn, call a common event. That common event would have a conditional branch checking if you have a Broken Bottle. If you don't, nothing happens. If you do, it Forces Action of a "Shower of Broken Glass" skill, (Or, alternatively, Shows a Battle Animation and Inflicts Damage. Your choice.) and maybe reduces the number of Broken Bottles by one.
The other way is scripting. There, I cannot help you, but there's no shortage of skilled scripters here who can.