Mine have a very thick layer of horse shavings - say 2nd index finger joint in depth? I find a deeper layer needs to be changed far less often than a shallow layer as the shavings can properly wick the wet from down to the lower layers, keeping the top more dry for the piggies. And then there's hay on top of the shavings in half the cage.
So with this in mind, I remove the damp patches every 3-4 days (ish). My piggies have certain places where they always poo/ pee, but in addition to that they usually pee in places where they also poo, so if there's a pile of poos it probably means there's a lot of wet which need removing underneath.
I only change the wet megazorb every 3 days or so and then I only scoop out the wet areas and replace with fresh. I find it works very well in the hay tray - not sure how well it would work in an entire cage.
This is basically what I do across the whole cage! I remove the wet bits, and sort of pile up the dry on one side of the cage so as to make sure I've got everything. I clean the base under any pee spots removed, but not the bits of the base which have stayed dry. I just use my hands and a binbag very near rather than any sort of scoop; I find it quicker and more effective.
Then when the wet stuff all removed I shove the dry stuff back over and add more clean to it. Usually the 'clean' substrate will go in their bed area, meaning it will be peed on and come out next time, while the 'new' substrate goes everywhere else. So overall the substrate usually stays in the cage for about a week, week and a half maybe. But it's added and removed in sections as needed, because I don't see any point (financially or environmentally) in removing clean dry substrate.
Sooo, from the options you give
How does one "spot clean" this type of bedding? The "poo picking" I'm used to is almost impossible! The options I see are:
- Scoop out the most heavily-used areas (corners) every day and refill with fresh bedding
- Take off the "surface" layer, along with poops, and add some fresh bedding
- Mix or stir around the bedding so poops and soiled areas are evenly distributed and not concentrated
I would very much go for number 1. Depending on the depth of substrate you give you may find it works better to do it slightly less often than every day. I say this because on days where I ever have to clean out more regularly to e.g. make timings fit for when I'm away, I find it *much* harder to identify which are the soggyish areas. But this is because the substrate I use is very good at wicking the moisture down to lower layers. I've not used Megazorb itself for piggies.
Number 2 could work, but again re. moisture wicking - you might be taking off the dry stuff and leaving the wet.
Number 3 just sounds like you'd be wasting money and resources. But also then you'd have to clean ALL of the substrate out at some point in one go. Which is quite a big ask in terms of how much volume that actually is to cope with. I mix up a little bit when I add new stuff to the clean old stuff, but I wouldn't mix up dirty substrate with clean.
