When I was still wrestling, I knew wrestlers who would "train" their bodies to sweat leading up to a big competition. They'd just spend time in a sauna/steam room after practice with a big bottle of water, sweating their balls off, so when it came time to make weight and sit in that sauna without a bottle of water they'd be sweating like crazy. I never did it, and don't know for sure if it actually works physically, but they may have been onto something (even if it was only a mental thing).
Agreed. Your first competition shouldn't be so much about the results as just getting out there and getting some experience on a competition platform. No need to add making weight on top of everything else you'll be doing for the first time. Just compete at whatever weight you're walking around at (I didn't haha, but again, I was transitioning from wrestling so dropping weight wasn't a huge deal).
I do something very similar (although I prefer to think of it as "dieting down" and "managing my fluid intake") though I would caution against overdoing it. I know I don't need to tell you Koing (I can remember your frustrations a few years back being stagnant while trying to stay in the 85s) but figured I'd mention it anyways. With a 2 hour weighin you only have so much time to recover nutrients/fluids, and if you're severely carb depleted and/or dehydrated when it comes time to step on that platform, you will lift shitty. I bombed out at nationals at least partly because I somehow ballooned up to 112.5 10 days out, and then weighed in at 104.0 on competition day (by the time the competition was over and I was back at the hotel and had had dinner I was back up to 108-109 haha).