Having diarhea in the shower, most often after a night of heavy drinking and are too tired to make it to the toilet. The phrase is derived from the sight of the loose stool being dissolved away in the shower drain leaving only remnants too large to pass through the grate.
"God, I was so tired I just couldn't make it to the toilet so I ended up panning for gold in the shower"
When someone who is delivering a Cleveland steamer is also receiving a golden shower and residual urine falls on the recipient of said Cleveland steamer