It was easy, I went to the dollar store and bought 4 flat scrub bushes and unscrewed the backing plate then reattached the brushes end to end in a row to a 1x4 piece of wood I cut fit across my shower floor. Now its real easy to clean up at the end of the day even if I was walking on blacktop or something I just put a little soap on the brushes and can scrub my feet standing up. So much easier.
Your way sounds like more effort though, so it's actually lazier, cheaper and better for the environment to do it my way.
Be better for environment to make one of these cause it works even without soap, but plastic manufacture is a dirty business too. Have you ever read about the great ethanol scam ? They burn over a gallon of diesel making the gallon of ethanol in all the farm tractors and possesses to turn that corn into a gallon of ethanol they put in the gasoline. www.google.com/search?q=the+great+ethanol+scam To say my foot brush was environmentally unfriendly we would have to do all the math on soup usage and plastic making extra water real scientific like.
A gadget is always more of an impact than a body part. Plastic takes so much water and energy to make, let alone the oil, that anything with plastic just about automatically qualifies as ecologically crap.