How I choose materials

I pick the cartridge for the substrate, the movement of that joint, and whether the job is water or paint — not because the shelf said “universal”.

A prep cleaner takes off grease and residue. A primer builds a bridge on a porous or difficult face. They are not the same bottle.

Acetoxy silicone, neutral silicone, acrylic sealant and hybrid each have a place. Sanitary silicone for a shower is not a natural-stone grade; paintable acrylic is not for the shower tray.

If the tray moves, the substrate is dirty, or I do not have a verified buy link, I do not invent the advice or the button. Get the detail right first; then the material.