I'm thinking of using waterproof liquid nails {Rapid cure , PU, Selleys }, so that it is an once & forever job to caulk & chamfer "often wet" edges +gaps. Thickened bleach gel + tooth-brushing can then be applied to remove the fungal mould grown, if any, on hardened liq-nails every 3 months or so . In your case, u need to repeat the 4-big-step job once every 2,3 or 5 years depending on whether the sealing power remains. My doubt about Liq-nails is whether the 矽膠片(blue kit-5 bits) can refine the finish as nice as the silicone case, do u have experience to share on applying the 矽膠片 (blue kit-5 bits) on refining rapid cure & sticky adhesive paste?