Came across these in a £1 shop in Nuneaton last week. Not sure if other similar shops carry them but heck thats a LOT of rubber washers (some small enough to fit mixture screws etc) for just a £1. They're sold as 'tap washers' but they seem to vary from tiny to fairly big. Might be worth looking out for.
For anyone near that way, its right opposite the hole-in-the-wall type batch bar in the town centre, near the George Eliot statue.
