i have front loader and dryer on floor with bench over teh top iuts great
DD helps me put the clothes in and push teh buttons etc
she has never tried to get inside.

but i keep the doors shut and they have child locks on then, you have to push a button and pull really hard to open teh door. so never been an issue

DD also sits there and watches teh bubbles in teh washing machine it amuses her for hours lol