Looking at the photo, let me expand on why and where I suggest you liberally lube the spool. Since water can and will get past the threads it will seep into the area on the center section of the spool between the 2 orings. This area is located inside the hose at one end and the SPG at the other with a slight gap between 2 metal surfaces. It is pretty much impossible to properly flush out unless you dissemble the parts which none of us do. If it is not well lubed, sealed really, against this water, it will corrode, many times to the point where you can not get them apart without damaging something. Liberal application of your lube of choice in the area between the orings will help prevent the corrosion and damage. Some will claim that this will "attract" grit and grime but this area is encapsulated inside the hose end and dirt really cant get in. Even it this were true, a little extra dirt to clean off is much better than trashing a hose and/or SPG because the spool is corroded in and can't be removed.
