Just thought I'd add 2 cents about the "unwaterproof" mini Bics. What I do with all my Bics that are in kits is put a tight rubber cap over the important end; keeps water/dust out and might even prevent accidental gas release by lever getting pressed.

These rubber caps are the things you put on your fingertips for paper handling. No. 2 (typ. yellow) is perfect for a regular Bic, No. 00 (typ. red) is right for the mini Bic. Stationery/dollar stores, very cheap for a pack, other odd-ball uses.