When I notice an onset of RSI I switch to a thumb operated trackball for a couple of days. Also when I produce music and haven't enough space left besides my controllers on my desk for operating a conventional mouse.
If you're having to switch to hold it off it might actually be being caused by another ergonomic problem with your space.
I kept having to change things/switch out things to hold it back until I one day adjusted my chair/armrest height to above my desk and I haven't had an issue at all in 6 years since doing that.
