I like the line from the police in the link
... If you need to dispose of some meth or other drugs, just call us we will take care of it for y'all !
Sure, we will be happy to arrest you is the translation, at minimum you'll be considered an individual of note worthy of observation.
That would be the stupidest way possible to get rid of ill eagle drugs, if you chose to quit or somehow came in possession of such contraband.
I can't believe putting it into the sewage is going to create meth-gators at your back porch !
I'd find another disposal method, that is more eco-friendly than flushing it down the turlet, that also protects you legally and does not put you on police radar or in bracelets.