oh and no you should never ever advertise these kind of pictures... high paying customers with nice clean homes will be frightened at the sight of this and never call.
They will assume your equipment is disgusting and sucks this kind of mess all the time. Nobody cares about amazing before and after pics except other carpet cleaners or filthy dirty customers who might call with a $150-200 job.
I prefer the opposite, advertise super nice pics of really high end multi million dollar homes to scare away the customers in dirty apartments on a budget