What baby proofing stuff do yall use?

My oldest is 5 and diagnosed. My youngest just turned 3 a couple days ago and isn't diagnosed though suspected. (She was evaluated for free services and deemed as advance for her age but they said that's not an indication that she's not autistic too)

Both kids get into everything. One of the biggest issues we're facing is they get into our cabinet where we keep our food and dumping everything out, oldest claims she's making slime. They also get into our fridge and have turned it off entirely at least 3 times now and we've had to throw a bunch of food away twice because it went unnoticed until it was too late.

I bought self adhesive locks for the cabinet and the fridge but my oldest managed to just rip it off. I didn't want to lock up our food but I felt like I had no other choice. So much food was being wasted all the time.

My oldest is also tall and she's started to climb on things so keeping things on a high shelf isn't really an option either. I've tried this and she still managed to get things even off shelves I myself can't even reach at 5'2.5

I was gifted those little door alarms you peel and stick to doors that have a chime or alarm setting. I put it on their bathroom door because they kept going in there and flooding the entire bathroom with the sink. It's only partially worked. I don't want to lock the door because our oldest is finally starting to use the potty and only wants to use the small one in that bathroom. Moving the potty will make her not want to use it.

I really have no idea what to do. The locks didn't work. A baby gate to our kitchen might work but they can still access the kitchen sink and flood the living room again from the other side of the counter. They're both quiet when they're being mischievous so I don't always hear when they're up. I'd put an alarm on their door but it'd just wake oldest up when youngest gets up for water in the middle of the night and once she's up they're both up for the rest of the night.

I used to have video cameras in their room but it wouldn't let me know when they were up and moving. There were no actual alarms that would chime when it detected movement so the ones I have won't do much good at all (plus they're on wifi so I don't want to risk someone spying on them)

I thought about getting the baby proof door knob lock but that would prevent oldest from getting up and using the potty on her own. She won't tell me when she needs to go. It seems like she likes to go in secret then tell me after the fact.

What baby proof stuff have yall used that actually worked? We rent so it can't be permanent. I can use screws or nails in the walls though but anything more than that is a no go. I just need some type of solution other than guessing when they'll wake up and trying to be up before then (some days they'll wake up super early and it's hard to guess when they'll wake up tbh)

If yall have any advice please. Let me know. Because no amount of telling them not to do something or to do something a certain way etc is working. They just keep doing it regardless what I say or do. We can barely even afford to buy the stuff the first time let alone again and again because they waste it.