There are loads of products on the market (usually domestic and available in the supermarket) that are designed to tackle mould.
These products are basically variations of bleach. So the next time you need to eliminate some mould and are reluctant to pay £3 plus for smaller bottle, have a go with our suggestion; Selden Spray & Wipe with Bleach.
Remember that if you are trying to remove mould from mastic and the mold is black and spotty then it’s too late. The mould is set into the mastic and no chemical will remove it. The only solution is to cut it out with a Stanley knife or reapply the seal.