I've always used the elaborate praise method: make a huge fuss when she goes outside, and reward her immediately.

It sounds like Lulu doesn't have any understanding of potty training rights and wrongs. Keep her crate clean, and try to get her on a regular going out schedule.

It may take a little while ---- Sadie still makes mistakes, but cheese makes a big difference in her motivation.

Dogs and nature abhor a vacuum.
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