Is it OK to wash the deck of a sailing boat (mainly GPR, some wood) with a 'usual' clothes washing up powder (eg Dixan) or a 'usual' liquid soap (for dishes)?
Actually I should have asked wheather 'usual' powder or liquid soap will damage the deck or simply not clean it as good as a specialist product. This is the main concern.
We've found biological washing powder and a stiff brush to be an excellent way to clean our deck. Saves a lot of money on fancy 'boat cleaning' products.
Something that is pretty effective is "truckwash" or similar, which dissolves out the dirt otherwsie held in small crevices. But it is caustic so need fast rinse off.
For ultimate deck cleaner i have not yet found anything better than wessex GRP restorer system. Twp part, (1 part then rinse then 2nd part) it restores orginal grp colour and gets rid of any chalkiness. But prepare first with truckwash, and rinse heavily
I don't know if 'cmedsailor' refers to the locality of your boat, but you should be very wary of using any soaps or detergents for deck washing in the Eastern Med. If a complaint is lodged against you discharging soap suds overboard, you can be fined for pollution!
High Pressure cleaners do a pretty good job on non slip areas but take great care, particularly on older glass boats as the gel-coat can be thin and small holes will appear.