I have cleaning stuff in one cupboard. My locks are the kind that you clip onto the door handles (need to have two handles close to each other), sell them in packs of two at Asda. No drilling required.
I have in my contracts that parents bring suitable clothing for the weather and haven't had any probs. If I did I would send them home for raincoat/wellies (probaly why they always rememeber). Don't have space for different sizes of different weatr appropriate clothing!
When I registered I still had my old kitchen in, can't remember what I had on the doors. I think it was something similar (outside of door type) but not exactly the same, and were told were fine. I am due an ofsted inspection so will see what they say.
Not a childminder but having had a dc who could wrench cupboard doors open despite different childlocks, I moved all my cleaning stuff to the cupboards above the worktops out of reach. Still put childlocks on them. Bleach etc is on top of the cupboards, well out of reach.
Trouble is, what one Ofsted officer is happy with, another might not be! If you really don't want to drill holes, then you have 2 options. Either use the handle locks or move the poisonous cupboard! I think I'd try the handle locks first tbh. If your mindees aren't getting into them, then it's working for you and imho, that's the whole point of them and job done!