By "dust" do you mean powder or flake (finely ground mint leaves soaked with liquid)? Either way, the best way to smoke dry PCP (imo) is to mix it with tobacco and roll it up in a blunt. It burns slowly this way, and is spread out so you can gauge how high you're getting. You can always clip it and save the rest for later. Careful dosing is important with PCP, because just a little too much and you'll be "stuck" for hours, and that usually isn't fun, and can be dangerous depending on what type of setting you're in.
As for liquid, absolutely don't try to smoke it in a meth pipe. "Wet" is PCP freebase dissolved in ether, and ether is highly flammable, and has a low flash point. It would likely burst the pipe, and possibly harm you. Best way to smoke wet is to quickly dip just the tip of a cigarette in it, then pull on the filter end a few times to spread the liquid through the cigarette. Pull the filter out. I don't know if it's really necessary to pull the filter out, but it's what we do anyway. Then light the cigarette with another lit cigarette. An open flame will cause the cigarette to flare up, unless you let it dry first.