1. I clean my sex doll with Dawn regularly. No probs at all. It’s concentrated dish soap, so you don’t need much or to leave it on any longer than it takes to clean. Mix with water, wash, rinse. That’s it.
Mix about a teaspoon of Dawn in a couple of quarts of warm water, and dip in my washcloth, wring out, wipe her down, repeat until clean. Afterward, I rinse my washcloth in plain warm water, wring and wipe her down again, pat her dry. Let her stand for an hour or so then a baby oil rub, if it’s time for that, followed by powder/cornstarch once the oil’s been absorbed, or if I’m not going to oil, I do the powdering right after she’s dry from the wash.
2. It is very strange that the Dawn dish soap is leaving a film on the surface of your doll skin. Maybe try getting a clean cloth and some distilled water. The distilled water may absorb the film if it is a rinsing issue.
3. if it’s the water issue, I would buy a couple gallon jugs of water and see if it makes a difference. You can also mix the soap in a spray bottle and wash her that way.