Want to know the secret?
When you walk by potential candidates, you just turn your head towards them & instead of asking for pot, you just say this; "Purp, purp!" this works in any city, any state, any country. Eventually, someone will turn & say "Purp, purp!" back or they will say "Trees!" or "Grapes!" something along those lines. That is they're way of saying "I got or know where to get em..." & immediately, you stop them when they talk back & say "You know where to get them grapes?" & they will network with you. If they truly have product or know where to get it or are stoners themselves, they will repond to someone shouting "Purp, purp!" Don't say it soft either like your telling a secret, because then they will know your asking. You don't want it to look as if your asking, this way it'll keep you out of trouble. You want to say it louder then regular talking but softer then yelling. Just enough for them to hear & maybe someone standing 10-feet away as well.
Imagine if you walked by someone & they looked your way & said "Purp, purp!" Aren't you going to say something back? Even something like "Hell yeah!" even that is a legit response to someone knowing where to get it. Stoners communicate in different ways, this is my way of communicating with them when traveling to areas I am not familiar with (Drug wise). You will always get a response, 100% of the time from the person & your not actually asking, your letting them talk back, then asking. THIS ONLY WORKS WITH BUD! For whatever reason, bud smokers are way more mellow & they aren't offended by this, they actually enjoy hearing another fellow stoner yell something along the lines of weed.
Don't try to yell "Yayo!" because coke dealers take offense to that because of the seriousness of the drug & might kick your ass. Or they might think your accusing them of slanging coke & if they are, they don't want it announced to the world. Bud smokers, they prefer you announce your habits to the world.
It'll work & you don't have to worry about asking around or being afraid. Don't worry about getting embarrassed by people that don't smoke & hear you. Because 8 out of 10 people that don't smoke & you yell that to them won't even know your talking to them & won't even think twice. There is so much talking & noise in Vegas that nobody is going to laugh at you for yelling that, chances are they already heard or seen worse in Vegas by that point of they're visit.
It's just one of those phrases that appeals to stoners ears & makes them want to see who said it...
EDIT: After you yell that, if someone turns & looks at you, but doesn't say anything, just look at them in the eyes & say "You know where to get them grapes?" Because that person might know but they might not get the slang your using to ask. The worse that'll happen at that point, is they'll ignore you & keep walking or they'll just laugh or say "Nah, sorry bud..." Usually if they turn & smile at you like "Yeah, that's whats up!" then they are def. candidates that probably don't realize your asking & just think your supporting. Make sure you ask them too.