Just soak in acetone for while. Dump it out. Flush with clean acetone, dump it out. Let dry well inside as-is, then oil it with whatever you have. ATF, air tool oil, 3-in-1 oil, sewing machine oil, etc. Lubricate liberally. When ready to run it, just prime it like any other engine and run it. Once running, it will blow whatever oil out that is in it. Most oils aren't compatible with methanol, so rinsing it out with any kind of alcohol isn't going to do much good.