My routine is first to put on a pair of disposable blue nitrile rubber gloves before handling any of the sewer stuff. With sewer hose connected, I'll dump black tank, while a dedicated short garden hose adds water to the blank flush fiting. After 4 or 5 minutes, I'll cose black dump valve, open gray.
When that's empty, 2 taps on the sidewall, and my better half dumps a kitchen sink full of clean, hot soapy water. This does a final rinse of the hose, and leaves it clean.
I do not contaminate my potable water hose, or the outside hose bib, which is always sprayed with antiacterial kitchen/bath spray, when I am finished. I also spray the hose bib every time I arrive at a new site. Never know what the guy before me was doing.
