The holster for the nozzle is made of narrow, metal channel… open at the bottom… there are holes in the channel to place a long shackle lock (grandkids)… which limits the amount of space available to place any protective cover over the nozzle…
A large part of the problem is the wind here… it blows our fine dust deep into anything and everything… something which is not secured somehow will eventually get dislodged or blown away…
taking from some of the ideas presented here… I had an Ah-HA moment over the weekend… I need to repair a cut garden hose… I removed an extra 8” from the repaired hose, folded over one end (to keep the dust at bay, and was able to fit it over the open end of the nozzle… it’s a TIGHT fit… both on the nozzle and just enough room between the nozzle and the holster…
It‘s probably not ideal (takes quite a bit of finagling to get it secured) but it’ll work for now… I hope…