An alcohol or strong acid will probably have a small effect on the fibers. Try rubbing (isopropyl) alcohol first. Hydrochloric acid might work, marginally. Sulfuric acid in a dry form is often used to make ester bonds, but aqueous solutions will have some effect on breaking them, but that will probably affect the plastic part more than you’d like.
Oh, and usually heat makes everything go faster, so if you can place the motor/actuator in a warm spot, or even inside of an oven below the water/alcohol boiling point, it will probably help.