Seeking a bit of advice

[TheGreatIni]

Hello everyone, so far my posts on this site have been...well, less than spectacular. And indeed, I don't think this one will be any different unfortunately.

Recently, I've purchased 'Cavorting Sponges' by Bob McAllister. From how the performance occurs it seems similar to the Chink-A-Chink trick (In this case, it utilizes sponge balls and two playing cards to cover the positions when you move the balls)

The basic mechanics of the trick I understand and practice as I can...I was wondering if anybody else has experience with this trick and could offer practical advice. Specifically in clipping the new sponges when I need them as that and...well...not making it horrendously obvious are my big problems.