I use Flash and warm water which is quite effective but if the upvc window frames have the older black rubber gaskets rather than the newer white ones, the black stains will be very difficult to remove.
Yes, I do use it in the dishwasher. It's as good as all the top brands. Try it for a few days..It's effing magic....And it saves buying all different cleaning stuff. Honestly try it!
pop down to your local building plastics suppliers and ask them for a bottle of pvc solvent cleaner its less than �5 a bottle and it will last you months just a quick wipe over will bring them up like new but only do them once every few months
etype, Solvent cleaner is good for getting out stains but be warned it can take the outer layer off and leave a dull finish.
If you want solvent cleaner ask for a Winzer Wurth Type 32 or equivalent.
Do not rub this cleaner in too hard and make sure you buff off with a dry cloth.
Before you do that there are uPVC cream cleaners that fitters use after they have finished installing windows. A litre bottle should cost about �5.00. Rgds Al
Forgive me for being a bit dumb but about the ARIEL POWDER in the DISHWASHER...Do you mean you use it on a cloth to clean the inside of the dish washer or do you put it into the powder section & put it on a wash?