In my opinion Stain guard on carpets is one off the biggest rip offs, off this century, i always ask the customer when booking if the item is stain guarded and 9 out 10 that say yes and follow up with how rubbish it is. My pitch is save the additional money and have the carpet cleaned again in 6 months, they love the honesty and i end up with the majority of jobs, we then diarise to give them a call, and they often rebook plus additional work.
John