You can get this done even faster using the save and reload method by getting to this room. Each reload will get you 7 door unlocks. 4 in the room shown, 3 others in connected rooms. Character does not matter.
This is partially copied from the solution here. Solution for Three-Pronged Atac in Rare Replay
U = Up, L = Left, R = Right, D = Down
1. D, L, U.
2. L, U, Fall through the Trapdoor.
3. U, L, L Past Frankenstein, D, D, Pick up the Blue Key.
4. R, R, R, D, D
5. R, R (Blue Door), R, U, U, L Past the Demon, L.
7. L, U, U, L (Blue Door), L, L, U, U, R, R, Fall through the Trapdoor.
8. You will now be in the room with 4 yellow doors and the yellow key. Save your game
, unlock all the doors and reload the save as required.