I do a qwiso wash, 91% iso, below freezing. Roughly 10 grams of ground material/100ml of Iso. Put dried material in a mason jar and into freezer as is the iso. After a few hours, dump your Iso into jar with the herb. Shake violently for 30-40 secs and then immediately filter. I filter into a new mason jar and store up batches until I'm ready to evaporate it. Dump the qwiso into a glass baking dish; cover it with a lintless paper towel and blow a fan across the top of dish. depending upon volume, it will evap and be tar-like in12-36 hrs. Scrape the tar off with razor blade and do what you wanted. For a tincture I'll put a known amount in a known amount of 80-95% EtOH. It will dissolve in a day or so. Then doseage test, which may or may not be fun. If ultimate intended use is as edible, then decarbox the herb prior to freezing. If not edible, I turn the stuff into hash.
Don't be tempted to rinse, or re-extract the herb or else it gets dirty, bad tasting, etc. You will have gotten 85% of the THC in that 30-40second extraction so don't be greedy.