24/7 I've been putting cotton balls in my ears for a while now, takes a little to get used to the lower volume of everything else, but it really helps. I'm surprised at how loud things are at this point when I don't have them.
I can't tell what brand I'm using because I (unhelpfully for this case) throw away the box and just keep them in the plastic bag they come in, but every 6 months or so I'll go to Fred Meyer, Target, or Walmart and buy a big pack of the most expensive earplugs that say "sleep" on the box :-)