A lot of old things have been exposed to smoke – cigarettes, cigars, pipes, and/or soot from fireplaces. Water without a detergent of some kind will not get the smoke off because it is greasy. Since pressed glass was made to be used, there’s no reason you shouldn’t use warm water and a regular dish detergent. You can also try glass cleaner. You definitely don’t want a household cleaner that claims to leave things shiny – that usually means that it leaves some oil on the surface. The important thing is to create a set-up so that nothing is damaged, and doing the work is efficient and easy to do.