I'm still using battered to fuck SIS bottles I bought in 2011 or so. They're probably more dirt/mould than plastic by now but what doesn't kill you... slowly takes over your brain and starts controlling your thoughts...
We do have a bottle of Milton for this purpose. They get done fairly regularly and I store them in the freezer when they're not in use (no idea if this helps but assume it's less friendly to bacteria)
I'm still using battered to fuck SIS bottles I bought in 2011 or so. They're probably more dirt/mould than plastic by now but what doesn't kill you... slowly takes over your brain and starts controlling your thoughts...