Viva51, learning to listen your body is hard skill to learn and many factors chance constantly, but it is worth it.
That is one reason why it is good to start your routine very lightly, so, that you have time and opportunity to learn how your body (penis) responds to different things. If you are unsure to add or not to add another stretch it is better to wait a little, than rush and when you have reached the enough efficient point there is no need to add stretches (or jelqs) until it is necessary (old amount is more or less ineffective).
I have no experience about Wenchette, but as long as you don’t pull too hard with it, it should be OK. Just remember, that it is better to be safe, than sorry when it is about your penis.
Keep soft tissue soft.