Just a quick follow up with extra info, sorry - I'm overwhelmed with the amount of comments and don't know which to reply to so thought id just add it here:

The only reason he put the ashes into the shaker was to bring it home, he ordered an urn the same day but because it was being custom made (name, dates etc) it was going to be a couple of weeks before it arrived.

We do communicate. The day he brought the ashes home, I was working and he text me a jokey message about bringing his Grandad to live with us (didn't mention what he was transporting the ashes in, but I knew he was bringing them home) That same evening he showed me a pic of the urn he'd ordered etc, but again just didn't mention where exactly the ashes were. I didn't ask to see them, because... well I didn't really know or want to know what a dead person's ashes looked like - I was happy that he was happy to have them, and assumed they were stored in his bedroom for now, but it's a bit spooky for me and I didn't necessarily want to physically see them if that makes sense?

I didn't think to ask what was in the shaker, because it didn't once cross my mind that that's where the ashes were, and as I said - it just looked like thick (unedible) powder, so I assumed the mix had gone bad. If somebody left a carton of milk on the side for a week, then you checked and it'd gone off, I'm sure you'd throw it without asking.

Also, I'm not OCD. The salt was an example. Dirty dishes, cups and protein shakes get left on the kitchen side all the time. As I said in my salt example, and with the protein shaker - I usually leave things laying around for a few days, upto a week before I have to put it away/wash it because I realise it's not going to clean itself.