Durham's - Rock Hard Water Putty (Rating: 5)

This is by far my favorite wood putty for filling out holes and cracks. Easy to sand and smooth. And takes paint well and doesn't shrink. << It is says it can't be stained but I will try it one of these days >>.
3 parts powder to 1 part water. I just keep adding powder and mixing it real good until it looks like peanult butter then I know it's perfect for filling holes. And you get a lot 16 oz can for the money and don't have to worry about drying out. Just mix a batch as much as your job requires.