Most "home remedies" do not adequately address the source of the pain from a cracked tooth since the tooth is already permanently structurally compromised.
The pain usually comes from the pulp (nerve) within the tooth that is progressively irritated when the crack is wedged apart and from chronic bacterial ingress.
Some home remedies that patients have tried include:
Painkillers. These can relieve some of the pain and inflammation coming from the pulp while you are waiting for definitive treatment.
Oil of cloves, which contains eugenol (a compound with nerve sedative properties). This unfortunately tends to stain the tooth brown permanently.
Most patients with a cracked tooth are unable to chew on the affected tooth since that causes pain.
Ultimately, seeking timely treatment may allow you to prevent an abscess or loss of the cracked tooth, which may cost more to replace in the long run.