Switching ground with a switched jack

[DIY Bass]

This is not really stompbox related, but it's close :-)

I have made a Theremin from the Jaycar/Silicon chip kit for a workmate who wants to use it on stage.  It comes with a speaker and optional line out.  I have installed the line out components, and I have used a 6.35mm socket for the line out - one of the switching ones with 6 lugs - https://www.jaycar.com.au/6-5mm-stereo-insulated-dpst/p/PS0190

I am using the ground/shield switch to switch the ground to the speaker, so when a plug is inserted into the line out the speaker is disconnected. It works well, but this socket does not grasp the plug well.  I am worried that on stage it might pull out pretty easily.  I prefer the standard open type sockets, but the only switched ones of those I have seen only switch the tip.  Can anyone think of a way to use this to switch the speaker off, or suggest a socket that switches ground but hold the plug well?

Thanks

[FiveseveN]

I am worried that on stage it might pull out pretty easily.

The chief design goal for jacks was quick insertion and extraction in old-timey telephone switchboards. If this is a legitimate concern and not just excess caution just use XLR (and a switch).

[PRR]

to switch the speaker off,

If this is stage use, why switch the speaker?? The unit is what? a tenth Watt? The PA system is a hundred Watts. A listener has to be within inches to hear the internal speaker.

I have also used cleats or hooks to tie-off the end of a cable. Look on most plug-electric weed-whackers: there's a strain hook.