I've never heard of using lye. Using a caustic solution is not necessary, just make sure you clean the aluminium in acetone and soap and water several times before dunking in the anodising bath. The cleaning is the most important process. Do not touch with bare hands! My battery charger has a power supply mode so switching off and on isn't a problem. You can modify a battery charger to stop it switching, I did that years ago with a small one I wanted to use as a transformer, google it.