Is the 'rug doctor' the carpet cleaner good?

Yes they work well. Homebase hire them. If you have got a lot to do it may pay you to buy 5 litres of carpet cleaner from a janitorial supplier as the detergent they sell with the Rug Doctor is fairly expensive pro rata. Jeyes Enhance is the best on the market. You will need defoamer too. Although if you run out of that, grated soap works the same. Cheap old soap is best.