This is how you make a cucumber salve.
Or, well, this is how I make one. It's cooling to the skin and relieves itching:
Take one cucumber, peel, grate.
Pour ½ l oil into the top bit of a waterbath, add the cucumber to that, add water underneath, and let the water simmer for 1.5 hours.
Strain through a cheesecloth. You'll end up with most of the cucumber in the oil.
Pour into a large-mouthed container (a glass jar is ideal). Let the oil sit for a while, so a bottom muck (which includes all the water) forms. It takes from 4 to 7 days for the oil to clear (= no water left in it, = no mold in your oil and/or salve), but when we made a cucumber ointment the week before last, we were in a bit of a hurry, so we didn't let it sit for all that long (= rather large risk for mold, but hey, we made, let me count, 7 different salves + other bits'n'pieces, so it's not as if one salve that might go moldy is a big catastrophe).
Pic: Cucumber oil a few hours after straining.
Here you see the oil after a few hours. A lot of the water'n'things have already separated out.
After you've siphoned off most of the oil on top of the water (use a syringe, they're nifty), you can pour the rest of the oil into a glass. That'll make for taller layers of liquid, making it easier to get even more oil off that bottom muck. Here's the leftover oil in a glass, perhaps an hour after pouring it in there:
Pic: Cucumber oil leftovers in a glass.
After things have separated out once they easily separate again.
Once you have cleared off as much of the oil as you can get without also getting bottom muck, measure your take, and use 1 part beeswax (by weight) to 8 parts oil (by volume). Pour both into the top bit of a waterbath and let boil on full, else your beeswax won't melt.
Once it's all melted you can pour the lot into jars, let set, close lids, and label, in that order. Doing it that way makes for neat salve jars, with no salve all over the inside of the lid.
Me, I use a syringe to fill my jars. With the right size syringe (50 ml for 30 ml jars) it works a treat.