If it's full of homebrew, I'd chill it, open it and drink it if it's OK.
If it's full of NT Draught, I'd chill it, open it, have a taste to remind yourself why you homebrew then tip the rest down the sink
I have an empty Darwin Stubby, which is in a cupboard. The beer was revolting - just CUB megaswill, but worse from what I remember.
I like the idea of using it as part of the process to step up a starter. Or put it on the bar. Or both, and just have it on display when it's not on starter duties.