I've been asked a slightly left-field question by a composer friend, who needs what can only be described as a "squelch" noise for a piece he's working on (and which I will be playing next year). Imagine, if you will, the noise Disney might produce for a sea-slug character being poked with a stick.

While electronics can, of course, come to the rescue (and will if we can't find anything else), he would prefer something physical and percussive. And if anyone knows what that might be, it's the members of this august forum.

The sound will be scored and will need to be played on cue (and probably in time) so nothing too Heath Robinson (er ... Rube Goldberg for North American readers) please.

Thanks.

Thanks, Louis. I'll give that a try. I wonder if that would work on an 8" tom shell? That would have the benefit of giving me a mount for it, too.

You could also use a heavy balloon with water and air sealed in it. When squeezed quickly it makes a squashy sound. Also Green slime if you can find it in a toy store in a heavy balloon with some air sealed in it might work. Both make the sound when squeezed quickly. Very wet potters clay compresses between your hands might be the trick too. Keep these away from electronics when using them with the exception of a microphone over it. 
Good Luck
Danny