You might ask the specialist about using a 'cat-friendly Kaopectate' like Pro-Pectalin: Pro-Pectalin™ | Vetoquinol USA. Two simple ingredients, kaolin and pectin, that shouldn't interfere with anything else. I think I'd opt for the gel which is 'inserted' in the side pocket of the mouth. Here's the package insert: PRO-PECTALIN™ GEL
Human Kaopectate used to be the go-to some years ago......before the Einsteins who manufactured it added ASA to the formula, thereby ruling it out for cats.
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