I've been using bars of Kirk's Castile for my family's body-washing needs, but it's fairly expensive and we run through it quickly. We use Dr. Bronner's Liquid Castile for many of our other household needs, but I'm afraid we'll just run through it too quickly in the bath/shower. My kids aren't great at judging the best amount to use, yet. Any suggestions for something more cost-effective? I'm open to making something if it's not too complicated. Thanks!