Gross but practical question: how do you keep your external keyboard / mouse clean? 

I've tried isopropyl wipes and it doesn't seem that effective.

I have the same keyboard at work and at home but the one at home feels 100x nicer since I use it so much less.

Is it a lost cause?

Honestly, I just buy a new mouse every so often.
Wipe down the keyboard, dust it a bit — fine.
But deep cleaning? No chance.

I wash my hands a lot, mostly to keep the keyboard from getting too gross.
But I’d rather spend a weekend messing with firewall settings
than sit there scrubbing keycaps with a toothbrush.

Some people clean to unwind.
I debug OPNsense configs.