I knew that was a generalization, hence the "even if you halve it"..
so in other words you have no idea if even half the households in the country run a dryer for 30 minutes a day every day. how much energy does that 30 minutes use?
at this point you're just making shit up. the dryer issue would be for the appearance of energy savings, overall it wouldn't make a dent. there are much more significant ways to save energy