Welcome! first of all think i dont know what youre gonna purchase but before you do think to yourself if you will use it to the fullest extent to get the best reactions and not let it sit there in your closet on the highest shelf with the spiders! secondly dealing with kids and interacting with them is probably more difficult than you think . You may want to check out seriously silly by david kaye or kidbiz or crash course by david ginn. In addition you could get great tips from the kids show section here @ penguin.
Now back to your idea about rubbing the silk. A little while back i had an idea of starting one of my kid shows with an appearing cane the following way although i didnt buy it yet....
start off with the six flags song and dance withe the red hanky and wave it like a bull is charging. Then towards the end of the song turn it into a cane and introduce yourself!
Im not saying to do this rather try to be very creative. My intro alone takes around 3.5 minutes!!!!
I hope you have much success in the upcoming years