How effective? Not 100% for sure
On a recent trip to the Mid-Atlantic US we tried several repellent options that were not liquid, and sadly none was as good as even the "natural" non-deet spray we usually use. Did they make a difference? It's hard to say for sure, but they probably did. However, they certainly didn't leave us without bites even on the parts of our bodies near the sound sources. That's not a huge issue for me, as I don't react that much to bites, but my partner abandoned everything besides the tried and true spray by our third day.
Rating: 3 stars