A4K, have never heard of a powder and to my way of thinking you'd have to get to close to the nest and it will take time to work. The spray works almost instantly. There are tons of wasps colony/hornets around here (Arkansas), though the ones around here are mostly the mud-dauber type which are seldom agressive. I buy a case of this stuff and keep a can on the deck, garage, patio, on the boats, etc. Last year I had a huge nest inside the rolled up bridge cover. I emptied an entire can into the opening and the wasps (dead) came out like a waterfall. Counted 48 on the deck plus a few that survived.
There are traps also but I have never had any that work except for yellow-jackets which come to sugar. I always have several that come to my hummingbird feeders. This is the stuff I use as it is fairly cheap and often comes in a two pack