Swordless Legend of Zelda Cheevo Attempt Part 2 (Skip to the end if you like)
27Swords - Who Needs Them?
Two hours of grinding but we finally beat one room of 5 Blue Darknuts with 8 bombs. This basically exposes a trick to bombs that I never realized - they have direction! You're best off putting a bomb in a wall because the bomb explosion sends damage directionally (I know it looks like a big puff of smoke) and if its direction is opposite of where the Darknut is facing, it won't hurt him.
This leads to weird scenarios where you drop a bomb, the Darknut walks over it and it explodes behind him but doesn't damage him. Worse, it does the animation and sound like you did damage him, but he doesn't lose HP and it's hard to tell!
If you put it in a wall, it's almost guaranteed to be in the same direction or perpendicular, a;most guaranteeing damage. You'll need it for this challenge, it turns out.