[JoanneF]

Are you rewarding outside toilets? If so, how do you do that?

 

[JoanneF]

Since then I've switched the reward to "going back inside."

This could be your stumbling block.

Toilet training happens when the ability to hold his toilet meets the desire to hold it - what's in it for him? When a dog realises that outdoor toilets are rewarded, that's when he will try to hold, in order to win the prize. So your reward has to be immediate to be really clear that it's for toileting and not for anything else.

Keep the treats hidden or at least not available until he toilets, then reward immediately and generously. I'd switch to something that is only used for outside toilets. When he gets it that inside toilets get nothing but outside toilets make a sausage party, that's when he will have the incentive to hold until he is outdoors.

And, how do you react to accidents indoors?

 

[JoanneF]

That's a good idea, I'll try it. I don't react much to his inside accidents other than putting him in the timeout room (it's just an empty room with a glass door, he doesn't like it but doesn't freak out). I know you're not supposed to punish dogs so that's all I do while I clean up the mess.

The thing is, if he doesn't like it, then it is a punishment. So maybe try to find an alternative.