There is always the food colouring and water trick.
Add food colouring to water.
Mix water with petrol at about 10:1 and shake.
Leave overnight.
Syphon off the coloured bit that is now water, food colouring and ethanol.
Not such a hassle to produce a couple of gallons for storing your Brough Superior over the winter, but I couldn't be bothered for every day use.
Andy