My step brother has tourettes, he excessively clears his throat and while some strains bring it out more, there are other strains that make it a lot more manageable for him. I can't think of any he really enjoys off the top of my head right now, but really it's personal preference and what works best for YOU. If you have access to several different strains, find a few that work for you. If you don't live a medical state and you have to take whatever weed you get your hands on, you have to decide if the other benefits are worth the chance of your tics flaring up. Maybe buy a little bit, smoke a tiny amount and see how you feel, then if you like it get more if it's not too much of a hassle. On the black market, I'm sure you understand a lot of strains you get probably aren't what your dealer says they are, so unless you are really confident about your source you're always going to be taking a risk.