Sheetrock sounds like a bad idea for hides. BPs are pretty strong so the potential for them to break apart one of the hides and get crushed or hurt is there. Not 100% sure what you had in mind but the sheet rock doesn't sound like the best idea IMO. There are plenty of other things to make hides out of that wouldn't pose a safety risk.
A lot of people just give advice for cheap alternatives for caging bc that's what most people are interested in. If someone asked me for suggestions for caging I'd recommend them the most inexpensive items that would work correctly first just because most small-time hobbyists appreciate tips that can save a few bucks while still being safe for the snake.