MY ET vets use a mild disenfectant on CIDRS. I always use a new CIDR in donors or in heifers. I am not sure why, but I have had some issues with using used CIDRs in heifers, so I have quit doing it. I know at the U of S Vet college they through used CIDRs in the washing machine, and then let them air dry and they store them in a dark cool place in zip lock bags. I have always been afraid to do this, as I am afraid that too long in the washing machine would ruin them. I wash them in a mild disenfectant, let them air dry and put them in zip lock bags and store them in a cupboard in the office of the feedlot. I haven't had any issues with using them a second time in recips and cows.
I am not sure if CIDRS in Canada still contain more hormones than those in the US, but I used CIDRs a third time on a set of later calving cows to see if I could bring them back to calving earlier in the calving season. I used 10 cows that were calving in May, and I put the CIDRs in, and all the cows had excellent heats. They were AI bred, and all but one of them calved the next spring in March. The other one came in open. CIDRs in Canada cost more than in the US so it could be they still have more product in them. Normally, I use them twice and then discard them.
I have heard so many proper ways of handling CIDRs and storing them, that I am not sure if any are better or if they all are OK