That's because scrawny kids don't float well. When I was teaching swimming lessons, I used to allow kids to scull with their hands while floating if they were the "skin and bones" type because that was the only way to keep their legs up. Otherwise their legs would drag their whole body down.
Realistically, no; you can't use your pool because it's not going to be long enough to actually test their swimming ability and trying to do it this way will result in kids getting passed that should not be. There is a big difference between being able to swim 25' (the length of an average home pool) 3 times and being able to swim 75' one time. Swimming the 75 feet in one go takes a higher level of endurance, and that's a critical part of what you are testing for. About all the average home pool can be effectively used for is testing floating, and working on basic skills with a non-swimmer.
In looking back, some memories remind Kenyon why he stuck with the scouting program so long. He shared one of those stories.
One summer during camp, a teen had trouble climbing the tower. Kenyon encouraged him when he wanted to quit halfway up. Years later, the young man sent Kenyon a letter from boot camp in which he said, "When you gave me that confidence in myself to go up that tower, that allowed me to get through this training."
"That is the paycheck you can't cash but is absolutely priceless," Kenyon said.
The last few years that I attended camp, they would bring trainers in to conduct basic training for adults who had not yet completed it...back in the stone age before everything went online. During the week I was in camp with my troop, we would teach YP, Safe Swim Defense, Safety Afloat, and volunteered to open the pool at 0500 for "Polar Bear Swim" and mile swim workups. The rest of our "free time" in camp, we would utilize skills for the Ranger's projects...such as re-roofing the dining hall in 95 degree heat, replacing toilets in staff cabins, running the bush hog to cut the fields, rebuilding the OA amphitheater...things like that. Never got a badge for it....just a cheer at the closing campfire.