Renewing bathroom joints
This Masters Club video will show you how to renew bathroom joints.
For example, bad ventilation causes mould in the silicone in bathroom joints. Such silicone cannot be cleaned and the only way to renew the joint is to completely remove the old silicone and fill in the joint with new silicone.
Old silicone should be removed very carefully and the joint completely cleaned from residues in order to make the fresh silicone adhere well to join surface.