It's interesting to hear how everyone does things slightly differently
. I guess because every hamster is different and you kind of need to do what works for them specifically. Also, It's a good point about dwarfs and their burrowing so needing to change the substrate at the bottom as well, I hadn't considered that.
Personally I started with the 'german' method but found I changed it slightly over time to something that worked for Spike. I have a big litter tray so change that out every 5 days or so and do a spot clean at the same time. I clean out his nest (not completely) once a month or if I notice it's gotten a bit whiffy. Spike is a very tidy hamster though so with changing out his litter tray frequently I don't feel that the cage ever really gets dirty as such. Because of this I only do a full cage clean every 3 months. I used to do every 2 months but it seemed pointless because the cage just didn't need it. I do however then change out all the bedding and wipe down the cage with hot soapy water. I keep a small bag of used but clean substrate and when I'm done I'll sprinkle that over the top. The reason I do a full subatrate clear out rather than the 'german' method is because I found that the base collects the occasional stray poop and sand kicked from his litter tray, he also likes to bury his hoards pretty deep
. Toys I clean as needed but not at the same time as a full cage clean.
So that's what works for us