The club has a bucket there, but when I went to use it I encountered exactly what you described; the paint/grease was air hardened and the roller handle a mess.
The spray grease I was thinking of was whitish lithium stuff, but it might be too runny/clear.
So I hope somebody knows of a recipe for paint/grease that won't splatter when I roll it and might last a year in my garage sealed up between uses.
