Using those units may be a lot cheaper then hiring professional carpet cleaning company to do it for you. However with this cheapness comes great amount of labour that you will have to undertake and furthermore results will not be as good as one could achieve using professional equipment that companies are using.
I can say this after many conversations that I have been having with my customers after they used those units and truly have been complaining on those rentals. it is not coincidence that they are smell and that renting them out will cost you at least £40 for a day and that chemicals that you will be using with them will not provide very good results and will not even last for that long.
I can say that those units can do the trick and if you are ready to dedicate your entire day for working on your carpets I’m sure that you will achieve some nice results. Just remember that you need to have good back to operate those units and some understanding that carpets cannot be over moisture as it will be very bad for long term health of your family and yourself.
Using those units you have to remember to extract as much water as you can from the carpet to have them in good condition to dry and make sure that you have windows open to get them in optimum condition for drying through the day.
You can find those units in many local supermarkets and local hardware shops.