I use the "Wow! It's time" system which is every couple days or so. I usually don't go more than three days without showering, but it happens.
When I do shower I use this big super scratchy cloth that power-scrubs everything thing away. Washing with just soap makes it just lay on the top layer of dead skin.
I wash my hair with shampoo and conditioner once a week or so.
GROSS. I'm imagining clouds of dust mites and fungus buildup swirling in your shower and latching to your shower door whenever "WoW! It's Time"...
Me, I shower EVERY single day, right after I eat breakfast, and often a second time at night, and I don't even do manual labor or anything. And I wash my hair EVERY DAY. Last thing I want is to look like Professor Snape.