I would ad two comments.

One, on a troop campout the scouts set up an axe yard. All chopping and whittling takes place with the yard. Using a knife for incidental tasks such as cooking or perhaps cutting a line as needed are exceptions. This restriction makes it less likely that a scout will be "playing' with his knife in an improper mannor. It doesn't eliminate it but it makes infraction easier to manage as they all know the rules.

Two, a more common infraction is for some reason they tend to be less attentive to the safty issues when they're swingin' away, exactly at a time when they should be the most attentive. Especially the younger scouts who do not have the strength for using the tool over 10-15 minutes. I get more concerned when I see a group of scouts chopping up logs for firewood than I do when I see them whittling down a stick.

Also, they seem more likly to leave axes and saws in the axe yard unsheathed. Our scout quartermaster is supposed to keep track of the tools, but we don't seem to enforce it as much as we should. I think we need to step up our vigilance on this point.