Noise Engineering makes mutes that are 4HP for four independent mutes with normalling to the set of mutes. The mutes are passive but have active indicator lights if you choose to plug it into your power.
I have two units. They tend to work their way into a lot of my patches to create variation: controlling modulation. I tend to mute with a Eurorack mixer (Sir Mix A Lot) with built in mutes for audio.
As well as DivKid's mutes, check out Joranalogue's Select Four. It has three-way switches for mute/unmute/momentary usage as well as a selector knob for a separate channel using one of your four inputs.
If you're looking for automation of your mutes then you're getting into -switch- territory. The principle is the same except you can use a control voltage to select an input. Of course, if nothing is plugged into an input it serves as a mute.