Not sure how old you Scouts are, or if this is for regular or emergency use, but...

In case of emergencies, my kids and I all have Frontier Water Filter Straws by Aquamira in our kits. They are small and easier for the kiddos - no leaking, no need for a fire, and no need to measure or time tabs/drops. Just put the two pieces together and drink hrough the straw. (We don't use them regularly, we use boiling and purification tablets for that.)

Here's a link for more info: http://www.aquamira.com/product/aquamira-frontier-straw-filter/