Same here.
I used to keep a couple of bottles of water in the garage with bottle caps from fruit shoots to spray the bike down when it was raining or salty.
I don't have power or water in my garage so this was make shift solution.
I often carried another bottle of water to work and sprayed the bike down when I got there.
I would take the calipers off the mounts, leaving the hoses connected, and using a toothbrush and some old brake fluid or brake cleaner clean up the pistons and recesses, slider pins ect. And reassemble.
Usually in oct, jan and april. I didn't fully strip the callipers down on the wee for 3 years doing this.
And the bike was a high-ish miller and used for commuting.