The very best lubricant is Krytox 205. If you have put all that effort into cleaning the motor, you may as well use a fluoride based grease that is compatible with both metal, rubber, and plastic. It is usually used on the sunroof tracks. You can get a 4 0z tube for $100 on eBay or a 1 oz tube for $40 on Amazon. The advantage of a fluoride grease is that it does not oxidize or evaporate, so you will never deal with dried out grease again. It is worth the money for jobs just like the one you are doing, where the grease does not get contaminated by outside dirt. You can grease your motor and never have to do that job again.