Well, no. It's illegal (in any coherent district) to put hard chemical waste (like silver) into the wastewater. you either take it to, as you suggested, a local

Well, no. It's illegal (in any coherent district) to put hard chemical waste (like silver) into the wastewater. you either take it to, as you suggested, a local film lab, or you clearly label it, build up several gallons of it, and take it to a chemical treatment factory, or whatever distribution process you have to get it there. Like NileRed does.