Two things I do...
Using Gaffers tape...I tape a 2" x 2" square of foam to each top and bottom head.
I also have a thick-cotton winter bed sheet that I throw over the whole kit to kill the cymbals...
...though you can also remove them, or try the foam squares...but the sheet it quick.
The Gaffers tape makes removal easy, without any goo...unless you leave it taped on for days.
miroslav - miroslavmusic.com"Just because it happened to you, it doesn't mean it's important."