I love the wash it balls, in fact I still have a half used one that I bought this time last year, still going strong (I had that one for £3 from EBAY NO P&P!). I think you have to be choosy what you use them on. I don't wash my boys white school shirts with them, but I do use it for their other school clothes, underwear and pjs etc-with very good results. I have ordered this TSV (first order from QVC in months-no p&p woo hoo!) because my daughter has been using the eco egg for the last couple of years and swears by it, they have now changed the way the egg opens and closes so no more worries of it coming apart in the wash. I shall use it like I have used the wash it balls, for non-whites and things that are not heavily stained, which means the bio detergent I buy will last a very long time and it definitely does save me money.I love to use the balls on towels and bedding as I don't like the idea of detergent residue on bedclothes, both boys having mild eczema.
I like the idea of the tablets they are supplying to clean the machine, too. I do a hot wash with white vinegar fairly regularly but I am sure these tabs will do a better job.