After doing lots of research and reading the manufacturer’s instructions I used 23% hydrochloric acid, diluted 1 part acid to 4 parts water, to slowly and progressively clean the propeller. I rinsed it with copious amounts of water between each cleaning session of several minutes duration, which involved brushing it on with a 2cm wide brush made with the tail hairs of young horses from the exotic ElCheapo breed. No disassembly was required, though I did remove the anodes first. So I guess that is some disassembly, which was easy to do. Worth doing too, as the anode screws were not as tight as I remember doing them up. I’ll be making sure the threads are clean and dry before applying Loktite when reassembling.
I wanted to be sure there was no acid remaining active in amongst the works of the propeller, so made a bucket of warm, soapy water and slowly poured that over and through the propeller mechanism, blades and body, a couple of times. Lots more rinsing and it’s as clean as a whistle. Next I will redo the various locking screws with fresh Loktite 243 in clean threaded holes, then apply grease to the gears, to protect from oxidation and make the prop ready for launching. We won’t go to the lengths of a full PropSpeed antifoul treatment this time, as, after the first year in the water the propeller was not particularly fouled up.