A ten-pound weight plate from a weight set would work pretty well too. You can get 'em at almost any garage sale, or at almost any sporting goods store for dirt cheap.
We also had really good luck with that "finger foam" (has little triangular "fingers" that jut out of it... available in drug stores and cheaper than Sonex) cut to line the entire inside shell of the drum. It depends on what sound you're after because it really deadens the sound a lot and lessens the natural "ring" of the drum shell. In some cases, that might help, in others it might hurt.
That was a drum trigger that we wound up not using on his kit. The triggers, no matter what we tried to use, would not stay on the drum heads. Oh well.
Since I work in a plating shop, I have access to the ultimate duct tape replacement- the large stainless steel spring clamp. Lots of surfaces on a drum set come to mind as candidates for this kind of attachment. These are like oversized clothespins with BALLS. They've got spring tension like a healthy grip exerciser. I use them to fasten 1.5" chemical transfer hose to any sort-of flat surface I can grab with the clamp. The hose kicks back and wiggles like a firehose under full pump pressure and so takes some serious force to restrain. Since I'm usually not pumping water but stuff like concentrated nitric acid I don't want the hose getting loose and spraying down the area.
What a scene THAT would be at 20 GPM!
These clamps have shown themselves to fit the bill. In a non-corrosive environment they'll last for years and cost about $15.
And they leave no gooey adhesive all over what you've taped down. But you can't attach audio cables with them: it'll squash 'em!
Before I sold my acoustic drum set (2 weeks ago), I had a house-brick wrapped in an old sleeping bag inside my bass drum.
Worked great for almost 14 years.