The thing to realise about digital pitch shifting, especially older real-time digital pitchshifting - is that it is a destructive process that introduces artifacts to your sound. Maybe this is what you want, but I suspect all you really want is the pitchshift detune effect that they were aiming for, less the artifacts.
Imagine you have a perfectly digitised audio wave, and you want to raise the pitch. We can easily play back that sample at a slightly higher rate, and this results in a higher pitch. But - just like tape varispeed - the sample plays for a shorter time. To compensate for this, the digital algorithmn has to "time stretch" the sample. To do this, we need to create more audio information to make it play for longer at the higher sample rate. To make up this audio data, we can take parts of the audio wave and loop them, to stretch them out for longer.
There is a similar problem if we want to pitch shift the sample down - this time the sample would play for too long at the lower rate, therefore we need to discard audio data. We can find parts of the wave that can be thrown away.
It takes some time for the logical operations to figure out which parts of the waveform are best for looping or discarding. You will find that most of the early digital pitchshifters gave you some options. You could have a very small time delay (while it was calculating this stuff), but the results were fairly gnarly and glitchy. Or you could have a longer delay, which gave it more time to figure things out, and that resulted in a smoother output with less artifacts.
I believe the basic pitchshift chorus effect you want is basically two pitch shifts, one pitched up and one pitch down by a few cents. There will be a small delay as well - which fortunately gives depth to a chorus effect.
You can recreate this very well with most DAWS without using plugins. Simply clone your mono track to two new tracks. Use your best offline pitchshifting algorithm that most DAWs have. This is best done offline, where the software can make the best quality rendering instead of having to make compromised decisions in real time.
I would recommend +10 cents and -10 cents as a starting point. Pan the detuned tracks hard left & right. Shift these tracks forward by about 30 milliseconds (or use a delay - 100% wet - no repeats).
By tweaking the detune amount and the delay, I believe you could recreate the effect you want very well, and probably better. On the other hand, if you are digging the noise & artifacts of the real thing, then nothing will replace it. You could try grunging your detuned tracks slightly with perhaps a bitcrusher or distortion, eq, pipeline impulse etc, etc.