i am going through a similar situation, however Krystal is almost 2.. so there is abit of an age difference.

she is constantly in the pantry, fridge or toilet. and i mean constantly if i tell her no, she will yell and scream, to the point where i feel like walking straight out the front door (bit of background - Krystal has never ever been a crier, even as a baby, she never cried for more than maybe 5-10 minutes and that was a hungry cry.. so for me, crying/screaming is hard to cope with!)

over the last 2-3 days i have been wondering should i ignore what she is doing, rather than say 'Krystal, close the fridge' 'krystal, come out of the toilet' over and over?
should i move her myself without actually saying anything to her and then say 'would you like to do some drawing' etc ?
should i just keep going as i am, but i feel that is not working..

sorry if im not much help, but i understand how you feel. perhaps giving it a go, being persistent and consistent in what you do in response to his tantrums might help!!

good luck with it!