I always battle flies and ticks and it seems nothing I try ever works. Either they have no effect at all or they last all of 15 minutes. I have used Horse and Stable because it's cheap but it doesn't last long, I used to use Tri-Tech 14 until it got so darn expensive. I liked that because it had sunscreen too which worked great for Chanti and actually seemed to last longer. I used Wipe without diluting it for ticks and it killed them after a couple days but didn't seem to keep flies off.
I've tried a natural cinnimon based spray that seemed to just attract them, I've used a homemade mixture of pine-sol that didn't have any effect. Vinegar has no effect either.
So if anyone has used a spray that works really good let me know. I feel bad for Sundance because his tail is still too short to really do any swatting so he's constantly fighting them.