I transformed my mouldy sealant in 15 mins using 1 supermarket item - and it's not vinegar 0 09.11.2024 07:00 Express.co.uk Mould growth is common in bathrooms because it is a damp and warm environment. Silicone sealant is particularly prone to mould growth because it is exposed to high levels of moisture around baths, showers and sinks.