Well I'm not really the best person to answer this as I class myself as a complete failure in toilet training department :oops:
with one dog who took 9-10 months to house train and another who (fingers crossed that he doesn't let me down in the near future) is only just there at almost 8 months :wink:, neither of whom have ever had the savvy to ask out.
I work for 3 1/2 hours in the morning and 1 1/2 hours in the afternoon and they are both clean when I'm out. In between walks, when we're just at home I let them out every 2-3 hours for a run round the garden and to do the toilet and this seems to work fine. On nice days though, I do as you do, and just leave the door open for them to come and go as they please. More often than not if I'm not out, they won't stay out long - they just come in and sleep at my feet :roll: :roll:
I've only ever had one dog before (OES) and he only barked about 3 times in his whole life I think - when he wanted in or out he scratched the door - not the best idea - I think there are still big gouge marks in the door at my dad's house 8 years later..........what can I say..he's not big on DIY
I'm glad my two don't bark to get out, they bark for every other reason :roll: so that's quite enough barking but I do wish they'd whine or something.
I've heard of people hanging something like a bell on the inside of the doorhandle and teaching the dog to push the bell with it's nose when it wants out. May try that one day - lot of other doggy misdemeanours to sort out first though!!!
Hope you find something that works for you.
Shirley