Here is the link to the Rinzaffo MGN waterproofing lime plaster: https://www.coreconservation.co.uk/rinzaffo-salt-resistant-scratch-coat/
The Rinzaffo MGN plaster is a lime plaster specially developed for damp and high-salinity environments. The most interesting characteristic of this plaster is that it’s waterproof and breathable at the same time. It stops liquid water ingress even with significant sideways pressure, but lets water vapours through, allowing the underlying masonry to breathe. Another interesting and important characteristic of this plaster is that it is highly salt resistant, resisting all types of salts: chlorides (sea salts), nitrates and sulphates.