How does he deoderise & protect without chemicals?
where abouts are you based?
Advertising zero chemical cleaning is some I've done in the past, You can clean carpets just using very hot water , most man-made fibres can carpet can be easily cleaned using just water as long as there is'nt any difficult stains
25p a ft is a good rate, he may be using a play on words, does he say half 'his' price or just half price. if some one around you does charge 50p a ft then he is 'half price'
Mike