I don't know what katol sealant is, but I had a similar dilemma when I needed the putty used for putting glass on casement windows. Inikot na ng tao namin lahat ng glass supply at wala daw sila, either they don't want to sell or iba na gamit. So I thought of buying a sealant from ace or wilcon for it. Turns out i have leftover Selleys in my utility cabinet and it did the job well.

Andami nang types of sealants available sa wilcon and the likes bro.