The trick about the shower is, "no one can hear you?" At least for me? I'm a singer, and a good one. But I'm self concious about singing in front of people? When I can sing alone, in my studio, is when I sing best... Likewise? If you're in the shower? And there's no one around? And people are either in another part of the house? Or out of the house... You can sing better, "because you're uninhibited..." It all has to do with our inhibitions.
"I also found it helpful to set up a second mic at the oppisite end to capture that extra body. :-)"
And an extra body in the shower? Priceless...