Derek, about thirty years ago we got the contract to clean all the vinyl chairs at the ICI offices in Runcorn, and as my memory serves me there were over a thousand of them. We started off with the Servicemaster powder for vinyl which I think was trisodium phosphate and it was very hard going with a lot of hard scrubbing. After we had done about twenty we were dreading carrying on, then I suggested that we try "Flash". I went out and bought some and we started to experiment and it was a lot easier. We found that the optmum performance came with 1 heaped tablespoon of "Flash" to 1 pint of near boiling water (Thick rubber gloves essential) simply wipe it on with a terry towel and leave about 30 seconds, wipe off and hey presto effortless cleaning. These chairs were twenty or so years old and were extemely grotty. Hope "Flash" haven't changed the formula. Hope this helps. Mike