@Amelia306 You stayed for 30 days and never cleaned the toilet because there wasn't a toilet brush? Why didn't you ask the host for one or go buy one? They're only a few bucks.
Hosts do not necessarily provide cleaning supplies for long term stays. If you look in the amenities section of a listing, it will say if cleaning products are supplied. You cannot assume that things are provided that are not offered.
Cleaning supplies is also something you could have asked for or bought. Not cleaning anything because there weren't cleaning supplies is a really lame excuse for leaving a place dirty after you've been there a month.
When you do some damage, you are supposed to notify the host right away, not "clean it up as best you can", and not mention it.
The host really shouldn't have an oil diffuser at all, though, and certainly not set where it can be easily knocked over.
No, guests are not expected to deep clean. They are expected to clean up after themselves and leave the place basically clean and tidy. Counters and stovetop clean, garbage in the bin, floor swept, fridge cleaned out, etc. And if you have stayed somewhere for a month, also washing the kitchen and bathroom floors, not leaving a month's worth of filth on it. Not cleaning the toilet for a month, nor washing the floor is disgusting and I'm not sure how you could live like that, but I know people do.
I'm not sure why the host keeps messaging you, though. One message to say you left the place a mess should be sufficient.