Think about your question a moment.
If you can do it with many needles, then you can most likely do it with less. But in my opinion more needles=better reaction and higher visibility.
Not necessarily in every case. If presented as a trick, then by all means stuff as many as you want in there. But presented as a more realistic feat, do less.
Think about it, if you could actually do it, does it seem more believable that you can do 10 or 15, or 25+?
Ask yourself if you want people to leave your show thinking they saw a magic trick, or a realistic feat/stunt. Answer that, then choose what works best for what you want.
In this case, less might be more.