Form to Function by Nigel Sutton is a great little book on pushing hands, mainly in the Ch'eng Man Ch'ing tradition but there are also some additional exercises provided to help you with developing necessary skills.
The book looks at single, double, fixed step and moving push hands, ta lu and fa jing exercises with a staff /pole. There is also a discussion about pushing hands for competition.
I really like the staff/pole exercises but I have a wing chun pole rather than a rattan one. I did have the pleasure of meeting Nigel Sutton many years ago when he lived in Hayes and I learnt a walking stick form from him. Sadly I can't remember the form but I do still practise the warm up exercises with the walking stick.