The real test of bolts has been in Thailand, where the rock is so acidic the seepage eats all but stainless steel bolts. I believe they have had great luck with the Hilti glue-ins, as RUMR said, they are cheap and impermeable.
With any glue-in, the holes have to be way cleaner than regular expansion bolts, for the very reason you mention: dust disallows penetration of glue into surrounding rock, compromising holding power. Because of the importance of permeation, glue-ins should only be used in softer rock.