refers to the actual shower which came into existence in the early 1800s. In contrast to the modern shower (shower in a can), which although gives a great sense of freshness, is no match to the cleanliness achieved by taking an old-fashioned shower. The term "old-fashioned shower" originated from The Stepbrother.
James: "wow i feel real nasty right now, toss me your shower in a can"
The Stepbrother: "nah man, it won't work, your too sweaty and nasty, what you need is an old-fashioned shower."