I've only been trying the one method. Just leaving her setup the way it is and putting him in. When I put him in he instantly heads to the back and straight into the hide with her. I don't know if thats a good thing or even a bad thing. But I've never witnessed a lock but then again I've never lifted up the hide while they were both in there.

Funny thing is when my male is in his tub he sits on top of his hide. but when he goes in with her its straight into her hide.