I suppose it also begs the question of why you don't want to use commands - is it that you want a "legit" in-game way to do it?
Looks like the Entropinnyum is only for TNT, not other explosions, so you may be out of luck. The botania Tigerseye makes creepers both run away and be unable to explode, but it doesn't sound like that's what you're after.