Just because something is scientifically possible...

... that doesn't mean that we should necessarily do it.
Sacrilege from the Times:

A caffeinated bar of soap has been invented for people who are short of time.
Every time a person lathers their body with the soap it produces two coffee cups’ worth of caffeine. The effects are said to be absorbed within five minutes and last for up to four hours. The soap, called Shower Shock, is intended for people who are too busy to make a cup of coffee in the morning. Shower Shock soap is on sale through the US-based internet company Think Geek and costs £3.50.