This leads to increased Protein Kinase A , which phosphorylates the CFTR Chloride channel , and opens it. You get high levels of Chloride and water secretion. The poisoned cells gets sloughed, and you get rid of the toxin. The trick is keeping the patient alive for the 5 days or so. Boost Glucose and sodium, and transport increases a lot.
Water follows by osmotic gradient.
Chloride will also follow to maintain electrical gradient.