I have at two part question:
1. When do puppies start to clean themselves? I have three yorkies that are 14 weeks old; 2 boys and 1 girl. I have seen all three of them clean each other occasionally, but they haven't started cleaning themselves. At what age do they begin or is cleaning each other their first attempt at clean hygiene?
2. But here's the problem. As I said, one of the puppies in my litter is a very tiny girl and is 14 wks old. She is so little and so is her "pebbles" (vulva)

but she hasn't started cleaning herself yet. And on the other hand, I have seen her clean her brothers "Bam Bams"(penises), very thoroughly.
Her "pebbles" are in a deep set crease so it hasn't gotten clean with her normal bath time. I don't think water is getting into the crease. I know I could get it clean with a Q-Tip and maybe Baby Oil, KY or something that wouldn't be an irritant..... but I just don't know if I should clean it or what to safely use. I really worry that she could get an infection but I don't want to mess with Mother Nature if she will take care of it herself.