Tried it with an iron, with the waxed cotton between some curtain lining (plain cotton). It pretty much sooked all the wax out of the fabric - a little spray of water from a scoosher bottle, and with a rub with a finger, it was starting to soak in on the ironed bit, but was clearly beading on an untouched area. That was with an old Morphy Richards iron set to cotton. I tried a few more patches at lower temperatures, but it didn't seem to make a lot of difference (the iron maybe hadn't cooled down enough, though). At the moment, I think it takes too much out, but worth another try starting with the iron at the coolest warm setting, and working up.
For the record...
It's not a jacket, it's just plain fabric for some projects (like stuff sacks).
The tumble dryer bit of the washing machine packed in ages ago, and I'm too lazy to do anything about it.
The ironing board is a cheapo that's only used for ironing stuff for sewing. That said, there was only a little bit of bleed-through onto the cover.
A rub at room temperature with something absorbent is appealing. I really just want to get the oiliness off the surface.