So drano is predominantly lye, a common name for caustic soda, which is basically a substance made from ashes thats extremely basic and dissolves fats and proteins. But, it doesnt just do that, its also corrosive toward plastic and especially rubber, which is what every juncture in your plumbing system uses to keep water from leaking. Just as important, drano isnt neutralized when it leaves your house – It continues being drano when it gets dumped into the ocean, or rivers/lakes/streams. This is not good for wildlife, or for municipal sewage systems. This doesnt mean that you cant use Drano, it just means that you use it very rarely, as it will physically damage your plumbing system. Its much safer and easier to use boiling water, as your plumbing system is designed to accommodate that, and its MUCH more ecologically friendly. Also, dont flush wipes down your toilet, even if theyre marketed as flushable.