Kleen Bore .17 Caliber Brass Cleaning Jag JAG-17 Jags offer the most thorough method of bore cleaning, preferred by experts. Directions: 1. Saturate a Kleen-Bore patch with No.10 Solvent or Formula 3. 2. Drape the patch over the point. 3. Pass the jag with patch through the bore to remove residue and fouling. 4. Repeat with a dry patch until clean.