Peter - not sure where you are heading, but I have a separate laundry room. Wish I had a utility sink in the garage though.
David - here is a more simple explanation.
It is not uncommon for my car to sit 2+ weeks at a time, even longer in the winter. In the summer I take the old girl on long golf excursions - that is when I add Techron and get immediate benefits. But then she sits for two weeks again, and the rough idle returns. I am not sure a more concentrated/larger dose will provide more benefit. I think cars in general just don't like to sit unused for extended periods of time.
If you were me, would you buck up this fall and replace the injectors, or continue with the Techron additive on a regular basis.
Of course I have several other wants/needs for the car.
Thanks again, Michael