Doc, if you're determined to use yote P for a snare set, then yes, the flip top bottles are much easier. I can't exactly recall where I used to get mine since it wasnt long and I started harvesting my own and doing trades with other trappers who did the same. NWtrappers, the two you mentioned, possibly the snare shop, just make sure you get 100% P , those places are usually solid choices.
You can use sticks, pebbles, clump of grass, or better a natural funnel that you don't need to disturb, doesn't take much.
Either buy preloaded snares, or preload them yourself and KEEP ALL FOREIGN SCENTS OFF THE SNARE AND THE AREA, if it's a dumb coyote and you don't get it, you just gave it a graduate degree in how to avoid Doc's trap
Just for future. If you do get one, have a 50cc or similar syringe like from vet, feed store, or if you know a Dentist that can get you one lol, open the yote, locate the bladder and drain what you can and put in a bottle. Sometimes you can get a good amount, but many times they crap and p when caught and have a small supply. Yote poop works just as good as p IMO, just try to source it from at least a few miles away. Used to trade plastic pickle jars of "scat" with other trappers as well.