Sniffer dogs work best when there's not many people around. Also, their sense of smell lasts for about 20-40 minutes, after which they can't smell jack shit.
Of course, at events there's a lot of people around, a lot of different smells so it's already hard enough for the dogs to smell anything.
If the dogs have been there for 1 hour already, you're pretty safe as their sense of smell is completely useless, and the only time they "sniff" people out is totally random, either cos the dog thought it smelled something or the cop motioned it to sit down next to a shady character.
Keep in mind (I know I'm repeating myself) - Dogs were NOT meant to smell stuff in a heavy crowd. They only work well with a few people around and in short periods of time.
As mentioned previously, the dogs don't actually smell the drugs, they smell the residue of the drugs. So if you were at home bagging your shit, and you were wearing the clothes that you're going to wear to the event, chances are particles of the drug will be stuck to your clothes, even if the drugs didnt touch your clothes. The dog will smell these particles, not the drug itself.
So always bag your shit couple days beforehand, preferrably do it naked in the bathroom so theres nothing for the smell to stick to, then thoroughly clean yourself and you should be good to go.
I usually just stuff it between my buttcheeks. Not quite inside my ass but just in the crack where even if I got strip searched, they wont see the stuff. They sure as hell aren't going to run their hand between your crack (unless you and the cop have a kinky fetish, then by all means get a room).
Also, attitude comes into play, play it cool, seriously dont trip out or panic, be nice, be respectiful, talk in a professional but not snooty tone and you'll be right. One time this guy in front of me got sniffed and he turned around and started to walk away fast. The cops were on him like a etheopian kid on a world vision food crate.