Hello,
If you want clear acetate leader, Chlorox (sodium hypochlorite) will certainly work. Just put your 15m un-spooled into a pail and let it sit a while. I have done this a number of times. Then just wipe the emulsion off with a soft cloth (most of it will just float away) and rinse well. Since polyester (estar) leader does not work with film cement, I use old acetate film lengths (stripped) for leaders with acetate based film. Clean acetate leader can also be dissolved to make film cement. This used to be an issue for me, due to my remote location, but Kodak film cement is still available - but not easy to find.
Why are you using leader in your camera? Daylight load spools have extra film to allow for a little waste at each end. 16mm cartridges, which are still available (though sometimes out of date) and re-loadable (with some care) have almost no waste.
Have I understood your question correctly? Why do you think polyester film will jam your camera? Are you trying to re-coat acetate with new emulsion? Oh, one more thing, that is a 16mm cine camera, isn't it?
Cheers,
Clarence