OK, I tried it, using the usual cable that connects the PC to the MG24, but it didn’t unbrick my MG24. It wasn’t a sleep problem. The program that bricked the MG24 that runs immediately when it is powered up screws up the clocks. Oh well…
Unless you have used an old library there should still be the “escape hatch” option available on D0.
Hold it low when resetting (or powering) and the app should not run. You can then re-flash.
If that fails, try the reset-recovery script… It should be in this post or the wiki.
What OS are you using?