Quoted from TaylorVA:

Getting to melt the witch is just not that difficult. I frankly don't know why people are having such a difficult time getting to it. Is it the witch Hurry ups or RESCUE MB.

Quoted from TaylorVA:

Personally I'll start by plunging to the pops to qualify monkey lock and start a HF mode. HF mode getting started feeds the ball back to the lower left and then shoot right orbit to lock Dorothy. Next ball shoot for witch hurry up and take her down with quick shots. At this point I'll either try to start ECMB or preferably Rescue. During rescue, if it's not qualified, start ECMB. With balls in play go for Witch Hurry ups to start FBF. I rarely shoot for rainbow letters unless I have one or two. I've melted the witch numerous times including on a single ball. Once in MTW I usually go for right orbits
And CB shots to qualify the final shots.

Quoted from tiesmasc:

To Start Melt the Witch you need to
Start ECMB
Start Rescue MB
Start a Munchkin Mode
Start Fireball Frenzy (by completing 3 witch hurry-ups and then starting another)
Then the big green insert below the witch will be lit and hitting her will start the mode which is a 2 ball multiball.
To then Melt the Witch you need to keep two balls in play and complete 4 shots (left VUK via spinner, left orbit, right orbit, wizard saucer - you can do all 4 separately or any mix of these (e.g. two orbits and two saucers)). Then you need to lock a ball in the castle VUK and while that is held shoot the other ball up the ramp where it goes around the house and drops in front of the upper flipper and you need to then hit the witch... and she is melted.
Then you get your award of Ding Dong the Witch is Dead multiball.
Personally I do go for the witch hurry-ups with my skill shots but then I actually ignore lighting ECMB locks (they just happen while I'm playing) and I try to get hurry-ups and YBRs... and when winkie is down (from the hurry up) I go for the castle to light rescue (as many times as I can so I have more balls during that multiball (though if speed is your goal only spell it 1x)). During the course of that RAINBOW gets spelled so I get my munchkin mode and the other MBs are qualified, locked, or achieved already so I'm good to go for the witch.