Probably not going to make any difference for you, but something to be aware of.
Pressing the crown will also stop an alarm/timer, you don't have to touch the screen.
if that doesn't help ....
you might be able to do it with shortcuts, you can make an action that will turn a specific alarm on or off, I'm assuming it will also stop an alarm that is currently sounding if you turn it off.
you'll need to have a specific alarm to target, so it can't be a "siri set an alarm at 3pm" kind of alarm, it needs to be one you've created and named in the clock app.
you will have to make a shortcut action for each alarm that you want to turn off, and if it's a repeating alarm that normally stays on all the time, you'll probably want to add steps to re-enable it, so that it will go off the next time it should.
depending on how you have things set up, your "work flow", and which alarms you want to stop, you might be able to make one shortcut that turns off all the alarms, just be mindful you won't accidentally turn off an alarm that's supposed to happen later. If you have a certain set of alarms that are "always on" then this might be easy to do.
or you might have to make a shortcut for each one.
once you're setup, shortcuts can be triggered with siri.
also not sure how this works with alarms that are on the watch vs the phone, if you'll need to talk to siri on the device that is actually going off.
