Practical cleaning routine for a commuter bike I regularly (almost daily) ride my bike, often in bad weather. I mostly ride on roads, but sometimes through parks, forest etc. on unpaved surfaces. My bike is usually rather dirty, at least the lower parts, especially when the weather is rainy. I do have mudguards, but they can't keep off everything.

I would like to keep it reasonably clean, both because it looks nicer and to avoid unneccesary wear. On the other hand, I don't want to spend an hour every week keeping it clean.

So what would you recommend as a cleaning routine that strikes a reasonable balance? Just hose it down? Only wipe critical parts? Use some wonder cleaner?

And are there functional problems or increased wear due to dirt, or is it mostly an asthetic problem?

Related question (more about maintenance in general):

Periodic maintenance tasks for bike commuters
Overview
As needed or as inspired, rinse off bike with water, clean with soapy water and degreaser, wipe down, rinse off. In practice, I do this every month or two or... of commuting. And yes, there are advantages to cleaning your bike; a clean bike will last longer, perform better, and serve as proof of the love of a proud owner.
Materials

rags
sponges
bucket filled with warm water and soap
scrub brush with plastic bristles
simple green or citri-solve in spray bottle
lube

Methods

Rinse bike off with water
Liberally apply soapy water to entire bike with sponge
Wipe dirt off everywhere except drivetrain with sponge
Wipe dirt off drivetrain with a dedicated greasy sponge
spray drivetrain with degreaser
wipe down drivetrain with rag
rinse again
apply lube to drivetrain
remove excess lube with rag

Notes
this answer focuses on cleaning the bike, but cleaning is also a good opportunity to check the bike for mechanical issues, including worn or loose parts:

tires
brakes
bolts
all other parts, including frame