The beams are wider than normal phasers in most situations. Like mariner cleaning carbon off slightly harder carbon or the crew cleaning the crystal graffiti off the ship.
I could see that being an energy-intensives thing though, and having worked on handheld high-current devices, I could totally see limiting the beam power/width settings to ensure you don't melt your hand. Or accidentally trip the overload setting...
here's a crazy idea: dedicated cleaning beams that make that kind of thing a "boop and we're done" situation. Or like.... Use the rifles. Those have to be able to handle more power, right?
But be careful if it has the post-Wolf-359 remodulation hotfix, because it's really easy to end up stuck in the nutation settings menu if you press either button 5 times within a few seconds.
You can disable this behavior with a long press of the firing button, which unsurprisingly got its own hotfix shortly after that.
It's the trigger - like a weedwhacker. The actual firing mechanism is on the bottom of the handle. You use your little finger. Any small children or pre-warp civilizations just assume it's designed to be convenient and fumble about uselessly. Nah: if Starfleet can't make a dangerous tool smart enough to say no, they make using it a pain in the ass.