I used to just whack a used tea towel or whatever under the machine before emptying it, so any spillages just go on that and tea towel goes in too of course. Would keep the bucket next to loo and kind of drain yucky water into loo.
We only use then in evening now and they just go straight in machine apart from poo ones that need a bit of sorting. My Ds finds it fascinating watching the poo in loo and flushing chain....mnn. Nice