I had gone through the - spittle; washing up liquid; potatoe juice; polish and even double glazed goggles, and found all wanting. Squinting and blinking fast wasn't much good either. A decent screen and 'reactolites' served me well for many years after. I did bump into 'Captain Krupp' on his B31 with electric oven one day in the Strand who was sporting one and asked him where he got it. Abroad, and for silly money. I passed.