pdreher, I totally agree with mbolddal I would get yourself the yellow poster putty from wallmart...97 cents only.
I have tried the blue tac and have some in my system. It does exactly the same thing as the yellow putty with just a little different feel to it.
Wallmart use to have a blue poster putty, but they don't carry it no more. The blue putty they carried did not keep as well. I have had the yellow stuff in my system for years with great results still.
Everytime my wife goes to walmart she knows to pick up about 7 or so packs cause I am always doing resonance in components and speakers with it. No lie, but there may be over 200 packs of it in my home theater by now!
Happy tweaking.