No firmware hack for PowerShot A3100 IS USB remote lock? No problem!

I'm trying to find a way to make some killer star trail images using my Canon PowerShot A3100 IS, but I keep running into some roadblocks with the max 15 second exposure time, and max 10 automatic sequential shots.

I was Googling around for an hour or so and found that CHDK could solve ALL my problems with capabilities for programming exposure time, number of shots, time between shots, you name it! The only problem? CHDK is not available for the PowerShot A3100 IS.

Well shoot, now what? I looked up P&S USB remotes and found that only some cameras can be tethered to computers, or rigged with some janky homemade micro USB remote.

My solution was to just tape a mechanical pencil eraser to the shutter button with the camera set on infinite rapid fire. With 15 sec exposure time, I should be able to set the camera up and record images back to back for some seamless star trails. I'll just have to throw out the first image of me messing with the camera to tape the button down, but after that I should get some nice sequential shots without touching the camera.