It's just a blend of various resins, and can be tinctured or made into resinous oils much like other resins.
Propolis is a blend of resins from plants found near the hive. Bees use propolis to seal the cracks in the hives, and aren't particular about what they use to do it. (That means that there can be toxics in there, but I don't know of any toxic resinous plants, at least up here.)
Resins need to be tinctured in 95 % alcohol; make a 1:5 95 %, and leave it in a dark corner for a week or three. With resinous tinctures it's necessary to shake once a day or so, as you only have resin at the bottom of your jar. You'll have bits left over once your tincture is "done"; they're either watersoluble (and not alcohol-soluble) or just leftovers, resins which didn't make it into the already saturated alcohol this time. Throw these leftovers into your next tincture, or into your next oil.
The implements you use in handling resinous tinctures will be difficult to clean: the alcohol evaporates off, leaving a whitish film of resin behind.
You can also throw your bits of resin into oil and leave that on a waterbath (or in a crockpot) for a few hours or days; a lot (but not all) of the propolis will dissolve into the oil and you can drop the rest into another batch of oil.
Strain either through cheesecloth. This will avoid bee legs (those bees knees, heh heh, I'm so funny) etc. in your oils and tinctures.