I have been thinking a lot about this since I was on a thread recently when someone was after a mooncup and was going to have one passed on from another mnetter.
I realised that there are lots of things that for various reasons we are "advised" not to reuse/recycle.
Some of these things:
Soft drink/mineral water bottles - often labelled "for single use only" or advised not to reuse supposedly for hygiene reasons.
Cot mattresses - new one needed for each new baby, I understand this is or was due to FSID guidelines. (I managed to pass dd1's mattress on to my mum's dog and very grateful she was too)
I had an Easter egg (Cadbury's) in a tin - bizarrely the tin had stamped on it something like "not intended for re-use - dispose of safely, recyclable steel". What is all that about? Especially as C'bury's this year made a big thing about selling some eggs without boxes to minimise packaging.
Car seats - even if you know where it came from(relative or whatever) I have read that they start to deteriorate after 6 years anyway is this true?
Reusable nappies - e-bay won't let you sell them, I think because there is a chance they may have been in contact with bodily fluids (you don't say!) Thankfully there are other places you can sell them.
Sorry for long post. Any other things people can think of and solutions for recycling these things?