Really, that is good advice. A 35mm film canister is a fairly wide open top container. Why limit yourself on the amount of cotton you can carry? Pack it in. If you are so far gone that you cannot dig a piece of cotton out of that 1 1/2 inch diameter opening with a finger, stick, knife tip, leatherman pliers, etc, how do you expect to light a match or strike a hot spark rod? If you can create a spark, you can dig cotton out of a 1 1/2 inch hole. Worst case, you take your knife (it is sharp isn't it?) and split the container lengthwise. It is just thin plastic. Any leftover can go into a pocket. I have mine packed full and have never worried about it.