GraphQL and URL IRIs

How can we setup a GraphQL schema/query that includes the forward slash in the URI?

We have resources in our graph database with identifiers such as:
ac:BIL0001/S/1

However, grahpQL gives an syntax error when you try and use ac_BIL0001/S/1 as the IRI ID in a query:

How do you escape the forward slash?

And a related question, why can't I use a normal URL as the IRI in a query, like this:

{ skos_Concept(iri: http://cc.atelier.co/packaging/pump)
{
skos_prefLabel
skos_narrower
}
}