I'm glad you brought this up. My precious boy Talyn (meorial here:
left me July 7,2019 just 5 weeks after his 11th birthday. I've already posted elsewhere about how wrong I was in waiting to get him help, because I thought something else was going on until it was too late. Aside from that GUILT, I too have not put away any of his stuff. His toys are still in the last spot he played with them (I have to vacuum around them). His dishes, litter box, etc all still in the same place. I found several of his whiskers, a few clumps of hair that I'm still finding around, and some of the sheddings of his claws. I have them in zip lock baggie along with some pictures and a claw paw print of his left front foot. I have them in a ziplock envelope. I don't want to clean any his hair off of my jackets or anything. I keep looking out over my balcony to the place where I buried him in the woods behind me that he loved to play in. I'll never forget that look of despair in his eyes, when I gently placed him in his carrier and drove as fast as I could. I buried him wrapped in one of his towels. I'm already starting to forget his scent :(
I haven't even cleaned his litter box yet, although there's no smell coming from it, so it's not an issue, but I just can't bring myself to do it. Everything in my apartment is exactly how he left it.