I used to pull my foreskin back, wipe my boogers underneath and roll my foreskin back over. I'd do this for about a week before i showered and have a nice collection. When I had a suitable amount, I'd grab a few Lego characters and have them venture to 'booger cave' as I'd affectionately named it and have them mine out the crusty boogers and store them in a little ziplock baggy. Whichever Lego team had mined the most over the month was the winner,

Must have done this for about a year then puberty kicked in and booger cave was closed off forever.

same