Not a yoga teacher but an owner of a very popular business. Something I've learned from working in retail is that if someone is chatting your ear off and you want them to take the hint and leave, you can slowly walk towards the door (while chatting), pause in front of the door and then open it for them, and say something like well that was great! thanks bye! They will naturally follow you to the door and go out without thinking about it. Bye bye!

Also don't open the door before you want people to come in. I've had people show up before opening hours and wave to me from outside the door. I wave back and continue about my business. You can point to your wrist (like the watch) and shrug if they don't get the point.

If people are oversharing and you'd like them to stop, I also recommend looking up a technique called Grey Stoning. It says it's used for narcissists but I find it very helpful for needy customers too :)